Courant, Richard. What is mathematics: an elementary approach to ideas and methods / by Richard Courant and Herbert Robbins. an elementary approach to ideas and methods / - Oxford: Oxford University press, 1941 - xxi, 512p. ; 23x16cm. Includes index. ISBN: 0-19-502517-2 Subjects--Topical Terms: MATHEMATICS Dewey Class. No.: 510 / COU-MAT