Feller, William On second order differential operators. (English) Zbl 0064.11301 Ann. Math. (2) 61, 90-105 (1955). Page: −5 −4 −3 −2 −1 ±0 +1 +2 +3 +4 +5 Show Scanned Page Cited in 27 Documents Keywords:functional analysis PDF BibTeX XML Cite \textit{W. Feller}, Ann. Math. (2) 61, 90--105 (1955; Zbl 0064.11301) Full Text: DOI