Velthuys-Bechtold, P. J. M.
Inventory of the papers of Evert Willem Beth (1908-1964), philosopher, logician and mathematician, 1920-1964 (c. 1980) / by P.J.M. Velthuys-Bechthold.
Beth, Evert Willem -- Archives -- Catalogs.
Mathematicians -- Netherlands -- Archives -- Catalogs.
Rijksarchief in Noord-Holland.