THESE two volumes are photo-lithoprints of the second edition of Vol. 1, issued in 1930, and Vol. 2, issued in 1937. The first volume contains seven chapters as follows: 1, the algebra of linear transformations and quadratic forms; 2, the development of an arbitrary function in series; 3, the theory of linear integral equations; 4, the basic principles of the calculus of variations; 5, the oscillation and eigenvalue problems of mathematical physics; 6, application of the calculus of variations to eigenvalue problems; 7, special functions defined by eigenvalue problems. Methoden der mathematischen Physik Von Prof. R. Courant Prof. D. Hilbert. (Published and distributed in the Public Interest with the consent of the Alien Property Custodian under License No. A. 82.) Band 1. Zweite verbesserte Auflage. Pp. xv + 469. 8 dollars. Band 2. Pp. xiv + 549. 8 dollars. (New York: Interscience Publishers, Inc.; London: H. K. Lewis and Co., Ltd., 1931–1937.) 2 vols., 14 dollars.