Rockland, C. (1975). Hypoellipticity and eigenvalue asymptotics.
Chicago Edition CitationRockland, Charles. Hypoellipticity and Eigenvalue Asymptotics. Springer-Verlag, Berlin, 1975.
MLA Edition CitationRockland, Charles. Hypoellipticity and Eigenvalue Asymptotics. 1975.
Warning: These citations may not always be 100% accurate.