Titchmarsh, E. C. Eigenfunction expansions associated with second-order differential equations. (English) Zbl 0061.13505 Oxford: At the Clarendon Press. 175 p. (1946). Page: −5 −4 −3 −2 −1 ±0 +1 +2 +3 +4 +5 Show Scanned Page Cited in 2 ReviewsCited in 208 Documents Keywords:approximation and series expansion PDF BibTeX XML OpenURL