1999/08/10 by M. M. Crum · 4 citations
Physics and Astronomy · #physics.hist-ph
published as Quart. J. Math. Oxford (2) 6 (1955) 121-127 · 9 pages, LaTex, with a forward by H.C. Rosu
arxiv created 1999/08/10 · arxiv updated 2009/12/01
Crum's seminal result of 1955 is archived here