Mkrtumyan, R. R. Linear differential equations of second order with rational solutions. (Russian) Zbl 0518.34011 Differ. Uravn. 18, 713-716 (1982). MSC: 34A30 34A05 PDFBibTeX XMLCite \textit{R. R. Mkrtumyan}, Differ. Uravn. 18, 713--716 (1982; Zbl 0518.34011)
Lepin, A. Ya.; Ponomarev, V. D. On topological imbedding of an interval into the set of solutions of an ordinary differential equation. (Russian) Zbl 0513.34015 Differ. Uravn. 18, 535-537 (1982). MSC: 34A99 34A34 57N35 PDFBibTeX XMLCite \textit{A. Ya. Lepin} and \textit{V. D. Ponomarev}, Differ. Uravn. 18, 535--537 (1982; Zbl 0513.34015)
Kapustin, N. Yu. On the theory of equations of mixed type. (Russian) Zbl 0503.35065 Differ. Uravn. 18, 1078-1080 (1982). MSC: 35M99 35F15 35D05 35A05 PDFBibTeX XMLCite \textit{N. Yu. Kapustin}, Differ. Uravn. 18, 1078--1080 (1982; Zbl 0503.35065)