Kholkin, Aleksandr M. A generalization of the theorems of alternation and non-oscillation for differential-operator equations of arbitrary even order. (English. Russian original) Zbl 1499.34232 J. Math. Sci., New York 196, No. 5, 632-643 (2014); translation from Ukr. Mat. Visn. 10, No. 3, 317-332 (2013). MSC: 34C10 PDFBibTeX XMLCite \textit{A. M. Kholkin}, J. Math. Sci., New York 196, No. 5, 632--643 (2014; Zbl 1499.34232); translation from Ukr. Mat. Visn. 10, No. 3, 317--332 (2013) Full Text: DOI
Kholkin, Aleksandr M. The fundamental solution of an operator-differential equation with singular boundary condition. (English. Ukrainian original) Zbl 1291.34100 J. Math. Sci., New York 179, No. 2, 261-272 (2011); translation from Ukr. Mat. Visn. 8, No. 2, 203-219 (2011). MSC: 34G10 PDFBibTeX XMLCite \textit{A. M. Kholkin}, J. Math. Sci., New York 179, No. 2, 261--272 (2011; Zbl 1291.34100); translation from Ukr. Mat. Visn. 8, No. 2, 203--219 (2011) Full Text: DOI
Rofe-Beketov, F. S.; Khol’kin, A. M. Connection between spectral and oscillation properties of differential- operator equations of arbitrary order. II: Applications of factorization and squaring. (English. Russian original) Zbl 0695.34022 J. Sov. Math. 49, No. 4, 1106-1113 (1990); translation from Teor. Funkts., Funkts. Anal. Prilozh. 49, 101-111 (1988). MSC: 34L99 34C10 47E05 PDFBibTeX XMLCite \textit{F. S. Rofe-Beketov} and \textit{A. M. Khol'kin}, J. Sov. Math. 49, No. 4, 1106--1113 (1990; Zbl 0695.34022); translation from Teor. Funkts., Funkts. Anal. Prilozh. 49, 101--111 (1988) Full Text: DOI
Rofe-Beketov, F. S.; Khol’kin, A. M. The connection between spectral and oscillation properties of differential-operator equations of arbitrary order. I: Sturm type theorems. (English. Russian original) Zbl 0699.34034 J. Sov. Math. 49, No. 2, 919-926 (1990); translation from Teor. Funkts., Funkts. Anal. Prilozh. 48, 101-111 (1987). MSC: 34C05 47E05 PDFBibTeX XMLCite \textit{F. S. Rofe-Beketov} and \textit{A. M. Khol'kin}, J. Sov. Math. 49, No. 2, 919--926 (1987; Zbl 0699.34034); translation from Teor. Funkts., Funkts. Anal. Prilozh. 48, 101--111 (1987) Full Text: DOI