Purvinsh, O. Boundary value problems for a degenerate elliptic system. (Russian. English summary) Zbl 0596.35051 Differ. Uravn. Primen. 36, 61-73 (1984). MSC: 35J70 35C05 PDFBibTeX XMLCite \textit{O. Purvinsh}, Differ. Uravn. Primen. 36, 61--73 (1984; Zbl 0596.35051)
Purvinsh, O. Investigation of the Dirichlet problem for a strongly degenerate elliptic equation. (Russian) Zbl 0511.35036 Differ. Uravn. Primen. 30, 97-104 (1981). MSC: 35J70 35C20 35B30 PDFBibTeX XMLCite \textit{O. Purvinsh}, Differ. Uravn. Primen. 30, 97--104 (1981; Zbl 0511.35036)