Kochubej, A. N. Elliptic operators with boundary conditions on a subset of measure zero. (English. Russian original) Zbl 0506.35029 Funct. Anal. Appl. 16, 137-139 (1982); translation from Funkts. Anal. Prilozh. 16, No. 2, 74-75 (1982). MSC: 35J30 47A20 47B25 47F05 35R20 PDFBibTeX XMLCite \textit{A. N. Kochubej}, Funct. Anal. Appl. 16, 137--139 (1982; Zbl 0506.35029); translation from Funkts. Anal. Prilozh. 16, No. 2, 74--75 (1982) Full Text: DOI
Kochubej, A. N. Symmetric operators commuting with a family of unitary operators. (English) Zbl 0459.47019 Funct. Anal. Appl. 13, 300-301 (1980). MSC: 47B25 47A20 PDFBibTeX XMLCite \textit{A. N. Kochubej}, Funct. Anal. Appl. 13, 300--301 (1980; Zbl 0459.47019) Full Text: DOI