Cheban, David Global asymptotic stability of generalized homogeneous dynamical systems. (English) Zbl 07796769 Bul. Acad. Științe Repub. Mold., Mat. 2023, No. 2(102), 52-82 (2023). MSC: 34C11 34C14 34D05 34D23 37B25 37B55 37C75 PDFBibTeX XMLCite \textit{D. Cheban}, Bul. Acad. Științe Repub. Mold., Mat. 2023, No. 2(102), 52--82 (2023; Zbl 07796769) Full Text: DOI
Bujac, Cristina; Schlomiuk, Dana; Vulpe, Nicolae The bifurcation diagram of the configurations of invariant lines of total multiplicity exactly three in quadratic vector fields. (English) Zbl 1527.34068 Bul. Acad. Științe Repub. Mold., Mat. 2023, No. 1(101), 42-77 (2023). MSC: 34C23 34A34 PDFBibTeX XMLCite \textit{C. Bujac} et al., Bul. Acad. Științe Repub. Mold., Mat. 2023, No. 1(101), 42--77 (2023; Zbl 1527.34068) Full Text: DOI
Turuta, Silvia Solution of the problem of the center for cubic differential systems with three affine invariant straight lines of total algebraic multiplicity four. (English) Zbl 1457.34049 Bul. Acad. Ştiinţe Repub. Mold., Mat. 2020, No. 1(92), 89-105 (2020). MSC: 34C05 PDFBibTeX XMLCite \textit{S. Turuta}, Bul. Acad. Științe Repub. Mold., Mat. 2020, No. 1(92), 89--105 (2020; Zbl 1457.34049) Full Text: Link
Bujac, Cristina The classification of a family of cubic differential systems in terms of configurations of invariant lines of the type \((3,3)\). (English) Zbl 1474.58013 Bul. Acad. Științe Repub. Mold., Mat. 2019, No. 2(90), 79-98 (2019). MSC: 58K45 34C05 34A34 PDFBibTeX XMLCite \textit{C. Bujac}, Bul. Acad. Științe Repub. Mold., Mat. 2019, No. 2(90), 79--98 (2019; Zbl 1474.58013) Full Text: Link
Schlomiuk, Dana; Vulpe, Nicolae The topological classification of a family of quadratic differential systems in terms of affine invariant polynomials. (English) Zbl 1474.58014 Bul. Acad. Științe Repub. Mold., Mat. 2019, No. 2(90), 41-55 (2019). MSC: 58K45 34C05 34C23 34A34 PDFBibTeX XMLCite \textit{D. Schlomiuk} and \textit{N. Vulpe}, Bul. Acad. Științe Repub. Mold., Mat. 2019, No. 2(90), 41--55 (2019; Zbl 1474.58014) Full Text: Link
Şubă, Alexandru; Turuta, Silvia The problem of the center for cubic differential systems with the line at infinity and an affine real invariant straight line of total algebraic multiplicity five. (English) Zbl 1474.34230 Bul. Acad. Științe Repub. Mold., Mat. 2019, No. 2(90), 13-40 (2019). MSC: 34C05 34C45 34C25 PDFBibTeX XMLCite \textit{A. Şubă} and \textit{S. Turuta}, Bul. Acad. Științe Repub. Mold., Mat. 2019, No. 2(90), 13--40 (2019; Zbl 1474.34230) Full Text: Link
Llibre, Jaume Limit cycles in continuous and discontinuous piecewise linear differential systems with two pieces separated by a straight line. (English) Zbl 1474.34224 Bul. Acad. Științe Repub. Mold., Mat. 2019, No. 2(90), 3-12 (2019). MSC: 34C05 34A36 PDFBibTeX XMLCite \textit{J. Llibre}, Bul. Acad. Științe Repub. Mold., Mat. 2019, No. 2(90), 3--12 (2019; Zbl 1474.34224) Full Text: Link
Cozma, Dumitru; Dascalescu, Anatoli Integrability conditions for a class of cubic differential systems with a bundle of two invariant straight lines and one invariant cubic. (English) Zbl 1397.34059 Bul. Acad. Ştiinţe Repub. Mold., Mat. 2018, No. 1(86), 120-138 (2018). MSC: 34C05 34A05 34C41 PDFBibTeX XMLCite \textit{D. Cozma} and \textit{A. Dascalescu}, Bul. Acad. Științe Repub. Mold., Mat. 2018, No. 1(86), 120--138 (2018; Zbl 1397.34059) Full Text: Link
Alexandru, Şubă; Olga, Vacaraş Quartic differential systems with an invariant straight line of maximal multiplicity. (English) Zbl 1397.34057 Bul. Acad. Ştiinţe Repub. Mold., Mat. 2018, No. 1(86), 76-91 (2018). MSC: 34C05 34C41 PDFBibTeX XMLCite \textit{Ş. Alexandru} and \textit{V. Olga}, Bul. Acad. Științe Repub. Mold., Mat. 2018, No. 1(86), 76--91 (2018; Zbl 1397.34057) Full Text: Link
Neagu, Natalia Invariant integrability conditions for ternary differential systems with quadratic nonlinearities of the Darboux form. (English) Zbl 1375.34002 Bul. Acad. Ştiinţe Repub. Mold., Mat. 2016, No. 3(82), 57-71 (2016). MSC: 34A05 34C20 34C45 34C14 PDFBibTeX XMLCite \textit{N. Neagu}, Bul. Acad. Științe Repub. Mold., Mat. 2016, No. 3(82), 57--71 (2016; Zbl 1375.34002) Full Text: Link
Şubă, Alexandru; Vadim, Repeşco Cubic systems with degenerate infinity and invariant straight lines of total parallel multiplicity five. (English) Zbl 1375.34047 Bul. Acad. Ştiinţe Repub. Mold., Mat. 2016, No. 3(82), 38-56 (2016). MSC: 34C05 34C45 PDFBibTeX XMLCite \textit{A. Şubă} and \textit{R. Vadim}, Bul. Acad. Științe Repub. Mold., Mat. 2016, No. 3(82), 38--56 (2016; Zbl 1375.34047) Full Text: Link
Vacaraş, Olga Cubic differential systems with two affine real non-parallel invariant straight lines of maximal multiplicity. (English) Zbl 1354.34061 Bul. Acad. Ştiinţe Repub. Mold., Mat. 2015, No. 3(79), 79-101 (2015). MSC: 34C05 34C20 34C45 PDFBibTeX XMLCite \textit{O. Vacaraş}, Bul. Acad. Științe Repub. Mold., Mat. 2015, No. 3(79), 79--101 (2015; Zbl 1354.34061) Full Text: Link
Bujac, Cristina One subfamily of cubic systems with invariant lines of total multiplicity eight and with two distinct real infinite singularities. (English) Zbl 1354.34060 Bul. Acad. Ştiinţe Repub. Mold., Mat. 2015, No. 1(77), 48-86 (2015). MSC: 34C05 34C07 34C45 34A26 34C14 PDFBibTeX XMLCite \textit{C. Bujac}, Bul. Acad. Științe Repub. Mold., Mat. 2015, No. 1(77), 48--86 (2015; Zbl 1354.34060) Full Text: Link
Cristina, Bujac One new class of cubic systems with maximum number of invariant lines omitted in the classification of J. Llibre and N. Vulpe. (English) Zbl 1310.34083 Bul. Acad. Ştiinţe Repub. Mold., Mat. 2014, No. 2(75), 102-105 (2014). MSC: 34G20 34A26 14L30 34C14 PDFBibTeX XMLCite \textit{B. Cristina}, Bul. Acad. Științe Repub. Mold., Mat. 2014, No. 2(75), 102--105 (2014; Zbl 1310.34083) Full Text: Link
Cheban, David Asymptotic stability of infinite-dimensional nonautonomous dynamical systems. (English) Zbl 1287.34049 Bul. Acad. Ştiinţe Repub. Mold., Mat. 2013, No. 1(71), 11-44 (2013). Reviewer: Christian Pötzsche (Klagenfurt) MSC: 34G20 34K20 34D20 39A10 37C60 37C75 PDFBibTeX XMLCite \textit{D. Cheban}, Bul. Acad. Științe Repub. Mold., Mat. 2013, No. 1(71), 11--44 (2013; Zbl 1287.34049) Full Text: Link
Şubă, Alexandru; Repeşco, Vadim; Puţuntică, Vitalie Cubic systems with seven invariant straight lines of configuration \((3,3,1)\). (English) Zbl 1275.34048 Bul. Acad. Ştiinţe Repub. Mold., Mat. 2012, No. 2(69), 81-98 (2012). Reviewer: Valery A. Gaiko (Minsk) MSC: 34C05 34C14 34C45 PDFBibTeX XMLCite \textit{A. Şubă} et al., Bul. Acad. Științe Repub. Mold., Mat. 2012, No. 2(69), 81--98 (2012; Zbl 1275.34048) Full Text: Link
Miron, Radu The generalized Lagrangian mechanical systems. (English) Zbl 1278.53028 Bul. Acad. Ştiinţe Repub. Mold., Mat. 2012, No. 2(69), 74-80 (2012). Reviewer: Bankteshwar Tiwari (Varanasi) MSC: 53B40 53C60 53B50 PDFBibTeX XMLCite \textit{R. Miron}, Bul. Acad. Științe Repub. Mold., Mat. 2012, No. 2(69), 74--80 (2012; Zbl 1278.53028) Full Text: Link
Gherstega, N. N.; Popa, Mihail N.; Pricop, V. V. Generators of the algebras of invariants for differential system with homogeneous nonlinearities of odd degree. (English) Zbl 1271.34040 Bul. Acad. Ştiinţe Repub. Mold., Mat. 2012, No. 2(69), 43-58 (2012). MSC: 34C14 PDFBibTeX XMLCite \textit{N. N. Gherstega} et al., Bul. Acad. Științe Repub. Mold., Mat. 2012, No. 2(69), 43--58 (2012; Zbl 1271.34040) Full Text: Link
Cozma, Dumitru Center problem for a class of cubic systems with a bundle of two invariant straight lines and one invariant conic. (English) Zbl 1235.34094 Bul. Acad. Ştiinţe Repub. Mold., Mat. 2010, No. 3(64), 51-66 (2010). Reviewer: Valery Romanovski (Maribor) MSC: 34C05 34C45 34C25 PDFBibTeX XMLCite \textit{D. Cozma}, Bul. Acad. Științe Repub. Mold., Mat. 2010, No. 3(64), 51--66 (2010; Zbl 1235.34094) Full Text: Link
Gherstega, N.; Mihail, Popa; Victor, Pricop About characteristics of graded algebras \(S_{1,4}\) and \(SI_{1,4}\). (English) Zbl 1204.34043 Bul. Acad. Ştiinţe Repub. Mold., Mat. 2010, No. 1(62), 23-32 (2010). MSC: 34C14 PDFBibTeX XMLCite \textit{N. Gherstega} et al., Bul. Acad. Științe Repub. Mold., Mat. 2010, No. 1(62), 23--32 (2010; Zbl 1204.34043) Full Text: Link
Puţuntică, V.; Şubă, A. The cubic differential system with six real invariant straight lines along three directions. (English) Zbl 1196.34039 Bul. Acad. Ştiinţe Repub. Mold., Mat. 2009, No. 2(60), 111-130 (2009). MSC: 34C05 PDFBibTeX XMLCite \textit{V. Puţuntică} and \textit{A. Şubă}, Bul. Acad. Științe Repub. Mold., Mat. 2009, No. 2(60), 111--130 (2009; Zbl 1196.34039)
Orlov, V. Classification of \(GL(2,\mathbb{R})\)-orbit’s dimensions for the differential system with cubic nonlinearities. (English) Zbl 1176.34044 Bul. Acad. Ştiinţe Repub. Mold., Mat. 2008, No. 3(58), 116-118 (2008). MSC: 34C14 PDFBibTeX XMLCite \textit{V. Orlov}, Bul. Acad. Științe Repub. Mold., Mat. 2008, No. 3(58), 116--118 (2008; Zbl 1176.34044)
Schlomiuk, Dana; Vulpe, Nicolae Integrals and phase portraits of planar quadratic differential systems with invariant lines of total multiplicity four. (English) Zbl 1159.34329 Bul. Acad. Ştiinţe Repub. Mold., Mat. 2008, No. 1(56), 27-83 (2008). MSC: 34C99 34A26 34C14 34A05 PDFBibTeX XMLCite \textit{D. Schlomiuk} and \textit{N. Vulpe}, Bul. Acad. Științe Repub. Mold., Mat. 2008, No. 1(56), 27--83 (2008; Zbl 1159.34329) Full Text: MNR
Gherstega, N.; Orlov, V. Classification of \(\mathrm{Aff}(2,\mathbb R)\)-orbit’s dimensions for quadratic differential system. (English) Zbl 1158.34324 Bul. Acad. Ştiinţe Repub. Mold., Mat. 2008, No. 2(57), 122-126 (2008). Reviewer: Alexey Remizov (Porto) MSC: 34C14 PDFBibTeX XMLCite \textit{N. Gherstega} and \textit{V. Orlov}, Bul. Acad. Științe Repub. Mold., Mat. 2008, No. 2(57), 122--126 (2008; Zbl 1158.34324)
Nartea, Cristina Computation of inertial manifolds in biological models. FitzHugh-Nagumo model. (English) Zbl 1134.92005 Bul. Acad. Ştiinţe Repub. Mold., Mat. 2007, No. 3(55), 102-110 (2007). MSC: 92C05 92C20 37N25 92C30 65C20 34D45 PDFBibTeX XMLCite \textit{C. Nartea}, Bul. Acad. Științe Repub. Mold., Mat. 2007, No. 3(55), 102--110 (2007; Zbl 1134.92005)
Diaconescu, O. V.; Popa, M. N. Lie algebras of operators and invariant \(\mathrm{GL}(2,\mathbb R)\)-integrals for Darboux type differential systems. (English) Zbl 1129.34028 Bul. Acad. Ştiinţe Repub. Mold., Mat. 2006, No. 3(52), 3-16 (2006). Reviewer: O. Makeev (Ulyanovsk) MSC: 34C14 34C05 17B66 PDFBibTeX XMLCite \textit{O. V. Diaconescu} and \textit{M. N. Popa}, Bul. Acad. Științe Repub. Mold., Mat. 2006, No. 3(52), 3--16 (2006; Zbl 1129.34028)
Tigan, Gheorghe On a family of Hamiltonian cubic planar differential systems. (English) Zbl 1116.34028 Bul. Acad. Ştiinţe Repub. Mold., Mat. 2006, No. 2(51), 75-86 (2006). Reviewer: Valery A. Gaiko (Minsk) MSC: 34C07 37G15 34C08 PDFBibTeX XMLCite \textit{G. Tigan}, Bul. Acad. Științe Repub. Mold., Mat. 2006, No. 2(51), 75--86 (2006; Zbl 1116.34028)
Starus, E. V. The classification of \(GL(2,R)\)-orbits’ dimensions for system \(s(0, 2)\) and the factorsystem \(s(0, 1, 2)/GL(2, R)\). (English) Zbl 1067.34038 Bul. Acad. Ştiinţe Repub. Mold., Mat. 2004, No. 1(44), 120-123 (2004). MSC: 34C14 34C05 PDFBibTeX XMLCite \textit{E. V. Starus}, Bul. Acad. Științe Repub. Mold., Mat. 2004, No. 1(44), 120--123 (2004; Zbl 1067.34038)
Le Van Linh; Sadovskiĭ, A. P. The centre-focus problem for analytical systems of Liénard-form in degenerate case. (English) Zbl 1053.34029 Bul. Acad. Ştiinţe Repub. Mold., Mat. 2003, No. 2(42), 37-50 (2003). Reviewer: Alexander Grin (Grodno) MSC: 34C05 34C07 PDFBibTeX XMLCite \textit{Le Van Linh} and \textit{A. P. Sadovskiĭ}, Bul. Acad. Științe Repub. Mold., Mat. 2003, No. 2(42), 37--50 (2003; Zbl 1053.34029)
Baltag, Valeriu Algebraic equations with invariant coefficients in qualitative study of the polynomial homogeneous differential systems. (English) Zbl 1051.34022 Bul. Acad. Ştiinţe Repub. Mold., Mat. 2003, No. 2(42), 13-27 (2003). Reviewer: Valery A. Gaiko (Minsk) MSC: 34C05 34C14 PDFBibTeX XMLCite \textit{V. Baltag}, Bul. Acad. Științe Repub. Mold., Mat. 2003, No. 2(42), 13--27 (2003; Zbl 1051.34022)
Lupan, Mircea; Vulpe, Nicolae Classification of quadratic systems with a symmetry center and simple infinite singular points. (English) Zbl 1057.34013 Bul. Acad. Ştiinţe Repub. Mold., Mat. 2003, No. 1(41), 102-119 (2003). Reviewer: Armengol Gasull (Bellaterra, Barcelona) MSC: 34C05 34C14 PDFBibTeX XMLCite \textit{M. Lupan} and \textit{N. Vulpe}, Bul. Acad. Științe Repub. Mold., Mat. 2003, No. 1(41), 102--119 (2003; Zbl 1057.34013)
Şubă, Alexandru Solution of the center problem for cubic systems with a bundle of three invariant straight lines. (English) Zbl 1051.34021 Bul. Acad. Ştiinţe Repub. Mold., Mat. 2003, No. 1(41), 91-101 (2003). Reviewer: Valery A. Gaiko (Minsk) MSC: 34C05 PDFBibTeX XMLCite \textit{A. Şubă}, Bul. Acad. Științe Repub. Mold., Mat. 2003, No. 1(41), 91--101 (2003; Zbl 1051.34021)
Cheban, D. N. Global pullback attractors of \(\mathbb{C}\)-analytic cocycles. (English) Zbl 1116.37301 Bul. Acad. Ştiinţe Repub. Mold., Mat. 2001, No. 2(36), 65-74 (2001). MSC: 37C70 34D45 37H05 PDFBibTeX XMLCite \textit{D. N. Cheban}, Bul. Acad. Științe Repub. Mold., Mat. 2001, No. 2(36), 65--74 (2001; Zbl 1116.37301)
Boularas, D.; Braicov, A. V.; Popa, M. N. Invariant conditions for dimensions of \(\text{GL}(2,\mathbb{R})\)-orbits for quadratic differential systems. (English) Zbl 1054.34059 Bul. Acad. Ştiinţe Repub. Mold., Mat. 2000, No. 2(33), 31-38 (2000). Reviewer: Günter Czichowski (Greifswald) MSC: 34C14 PDFBibTeX XMLCite \textit{D. Boularas} et al., Bul. Acad. Științe Repub. Mold., Mat. 2000, No. 2(33), 31--38 (2000; Zbl 1054.34059)
Port, S. A. \(\text{SO}(2,\mathbb{R})\)- and \(\text{SH}(2,\mathbb{R})\)-orbits for quadratic and cubic differential systems. (English) Zbl 1054.34061 Bul. Acad. Ştiinţe Repub. Mold., Mat. 2000, No. 3(34), 21-27 (2000). Reviewer: Günter Czichowski (Greifswald) MSC: 34C14 PDFBibTeX XMLCite \textit{S. A. Port}, Bul. Acad. Științe Repub. Mold., Mat. 2000, No. 3(34), 21--27 (2000; Zbl 1054.34061)
Şubă, A.; Cozma, D. Solution of the problem of the center for a cubic system with two homogeneous and one nonhomogeneous invariant straight lines. (English) Zbl 1005.34025 Bul. Acad. Ştiinţe Repub. Mold., Mat. 1999, No. 1(29), 37-44 (1999). MSC: 34C05 PDFBibTeX XMLCite \textit{A. Şubă} and \textit{D. Cozma}, Bul. Acad. Științe Repub. Mold., Mat. 1999, No. 1(29), 37--44 (1999; Zbl 1005.34025)
Hâncu, V. On the normal form and the reducibility of linear completely integrable systems with quasiperiodic coefficients. (English) Zbl 1024.37038 Bul. Acad. Ştiinţe Repub. Mold., Mat. 1998, No. 3(28), 29-34 (1998). MSC: 37J35 34C20 37G05 PDFBibTeX XMLCite \textit{V. Hâncu}, Bul. Acad. Științe Repub. Mold., Mat. 1998, No. 3(28), 29--34 (1998; Zbl 1024.37038)
Makar’, P. M.; Popa, M. N. Generating functions for comitants of differential systems. (Russian. English summary) Zbl 0840.34011 Bul. Acad. Ştiinţe Repub. Mold., Mat. 1994, No. 2(15), 90-95 (1994). MSC: 34A25 PDFBibTeX XMLCite \textit{P. M. Makar'} and \textit{M. N. Popa}, Bul. Acad. Științe Repub. Mold., Mat. 1994, No. 2(15), 90--95 (1994; Zbl 0840.34011)
Sadovskij, A. P. On sufficient conditions of the center for a cubic system of differential equations. (Russian. English summary) Zbl 0842.34033 Bul. Acad. Ştiinţe Repub. Mold., Mat. 1993, No. 1(11), 81-84 (1993). MSC: 34C05 PDFBibTeX XMLCite \textit{A. P. Sadovskij}, Bul. Acad. Științe Repub. Mold., Mat. 1993, No. 1(11), 81--84 (1993; Zbl 0842.34033)
Koz’ma, D. V.; Shubeh, A. S. Conditions of presence of four integral straight lines for a cubic differential system in the case of a center or focus. (Russian. English summary) Zbl 0829.34021 Bul. Acad. Ştiinţe Repub. Mold., Mat. 1993, No. 3(13), 54-62 (1993). MSC: 34C05 PDFBibTeX XMLCite \textit{D. V. Koz'ma} and \textit{A. S. Shubeh}, Bul. Acad. Științe Repub. Mold., Mat. 1993, No. 3(13), 54--62 (1993; Zbl 0829.34021)
Vulpe, N. I.; Nikolaev, I. V. Topological classification of quadratic systems with a unique third-order singular point. (English) Zbl 0913.34025 Bul. Acad. Ştiinţe Repub. Mold., Mat. 1992, No. 2(8), 37-44 (1992). Reviewer: N.L.Manev (Sofia) MSC: 34C05 PDFBibTeX XMLCite \textit{N. I. Vulpe} and \textit{I. V. Nikolaev}, Bul. Acad. Științe Repub. Mold., Mat. 1992, No. 2(8), 37--44 (1992; Zbl 0913.34025)
Koz’ma, D. V.; Shubè, A. S. Center conditions of a cubic system with four integral lines. (Russian. English summary) Zbl 0901.34031 Bul. Acad. Ştiinţe Repub. Mold., Mat. 1992, No. 3(9), 62-67 (1992). Reviewer: K.R.Schneider (Berlin) MSC: 34C05 PDFBibTeX XMLCite \textit{D. V. Koz'ma} and \textit{A. S. Shubè}, Bul. Acad. Științe Repub. Mold., Mat. 1992, No. 3(9), 62--67 (1992; Zbl 0901.34031)
Vulpe, N. I.; Nikolaev, I. V. Coefficient conditions for the coexistence of two singular points of summed multiplicity 4 in a finite part of a phase plane of a quadratic system. (Russian. English summary) Zbl 0993.34030 Bul. Acad. Ştiinţe Repub. Mold., Mat. 1992, No. 1(7), 51-59 (1992). MSC: 34C05 PDFBibTeX XMLCite \textit{N. I. Vulpe} and \textit{I. V. Nikolaev}, Bul. Acad. Științe Repub. Mold., Mat. 1992, No. 1(7), 51--59 (1992; Zbl 0993.34030)
Shubé, A. S. Conditions for the existence of a general integral of the form \(x^2+y^2\exp[\sum^n_{i=1}\phi_i(x,y)]=C\) in a fractional-cubic differential equation. (Russian. English summary) Zbl 0978.34021 Bul. Acad. Ştiinţe Repub. Mold., Mat. 1991, No. 2(5), 86-89 (1991). Reviewer: Klaus R.Schneider (Berlin) MSC: 34C05 PDFBibTeX XMLCite \textit{A. S. Shubé}, Bul. Acad. Științe Repub. Mold., Mat. 1991, No. 2(5), 86--89 (1991; Zbl 0978.34021)
Kalin, Yu. F. Conditions for qualitative pictures with centers for a complete quadratic system with \(I_ 9=0, K_ 1\not\equiv 0\). (Russian) Zbl 0891.34032 Bul. Acad. Ştiinţe Repub. Mold., Mat. 1990, No. 3(3), 68-71 (1990). Reviewer: K.R.Schneider (Berlin) MSC: 34C05 PDFBibTeX XMLCite \textit{Yu. F. Kalin}, Bul. Acad. Științe Repub. Mold., Mat. 1990, No. 3(3), 68--71 (1990; Zbl 0891.34032)
Popa, M. N. The number of comitants that are involved in determining the number of integral lines of a cubic differential system. (Russian) Zbl 0895.34022 Bul. Acad. Ştiinţe Repub. Mold., Mat. 1990, No. 1(1), 67-69 (1990). Reviewer: K.R.Schneider (Berlin) MSC: 34C05 PDFBibTeX XMLCite \textit{M. N. Popa}, Bul. Acad. Științe Repub. Mold., Mat. 1990, No. 1(1), 67--69 (1990; Zbl 0895.34022)
Kalin, Yu. F.; Sibirskij, K. S. Conditions for the existence of qualitative portraits with centers of a complete quadratic system with \(I_ 9\neq 0\). (Russian) Zbl 0891.34031 Bul. Acad. Ştiinţe Repub. Mold., Mat. 1990, No. 1(1), 17-26 (1990). Reviewer: K.R.Schneider (Berlin) MSC: 34C05 PDFBibTeX XMLCite \textit{Yu. F. Kalin} and \textit{K. S. Sibirskij}, Bul. Acad. Științe Repub. Mold., Mat. 1990, No. 1(1), 17--26 (1990; Zbl 0891.34031)