Courant, Richard Variational methods for the solution of problems of equilibrium and vibrations. (English) Zbl 0063.00985 Bull. Am. Math. Soc. 49, 1-23 (1943). Not reviewed Cited in 3 ReviewsCited in 149 Documents PDF BibTeX XML Cite \textit{R. Courant}, Bull. Am. Math. Soc. 49, 1--23 (1943; Zbl 0063.00985) Full Text: DOI