Il’in, V. A.; Filippov, A. F. The nature of the spectrum of a selfadjoint extension of the Laplace operator in a bounded region (fundamental systems of functions with an arbitrary preassigned subsequence of fundamental numbers). (English. Russian original) Zbl 0209.41302 Sov. Math., Dokl. 11, 339-342 (1970); translation from Dokl. Akad. Nauk SSSR 191, 267-269 (1970). MSC: 35P05 35J05 47A20 PDFBibTeX XMLCite \textit{V. A. Il'in} and \textit{A. F. Filippov}, Sov. Math., Dokl. 11, 339--342 (1970; Zbl 0209.41302); translation from Dokl. Akad. Nauk SSSR 191, 267--269 (1970)
Filippov, A. F. Differential equations with many-valued discontinuous right-hand side. (English. Russian original) Zbl 0141.27704 Sov.. Math., Dokl. 4, 941-945 (1963); translation from Dokl. Akad. Nauk SSSR 151, 65-68 (1963). PDFBibTeX XMLCite \textit{A. F. Filippov}, Sov. Math., Dokl. 4, 941--945 (1963; Zbl 0141.27704); translation from Dokl. Akad. Nauk SSSR 151, 65--68 (1963)
Filippov, A. F. Conditions for the existence of a solution for a quasilinear parabolic equation. (English. Russian original) Zbl 0121.08004 Sov. Math., Dokl. 2, 1517-1519 (1961); translation from Dokl. Akad. Nauk SSSR 141, 568-570 (1961). PDFBibTeX XMLCite \textit{A. F. Filippov}, Sov. Math., Dokl. 2, 1517--1519 (1961; Zbl 0121.08004); translation from Dokl. Akad. Nauk SSSR 141, 568--570 (1961)