Gimadislamov, M. G. A criterion for discreteness of the spectrum of a hypoelliptic operator. (Russian) Zbl 0494.35063 Mat. Zametki 30, 685-693 (1981). Page: −5 −4 −3 −2 −1 ±0 +1 +2 +3 +4 +5 Show Scanned Page Cited in 1 Review MSC: 35P05 General topics in linear spectral theory for PDEs 65H10 Numerical computation of solutions to systems of equations PDF BibTeX XML Cite \textit{M. G. Gimadislamov}, Mat. Zametki 30, 685--693 (1981; Zbl 0494.35063)