Levinson, Norman A simplified proof of the expansion theorem for singular second order linear differential equations. (English) Zbl 0044.31302 Duke Math. J. 18, 57-71 (1951). Page: −5 −4 −3 −2 −1 ±0 +1 +2 +3 +4 +5 Show Scanned Page Cited in 18 Documents Keywords:ordinary differential equations × Cite Format Result Cite Review PDF Full Text: DOI