Sommerfeld, Arnold Johannes Wilhelm, 1868-1951 Partial differential equations in physics / by Arnold Sommerfeld ; translated by Ernst G. Straus. - New York : Academic Press, 1949. - xi, 335 p. : ill. ; 24 cm. - Pure and applied mathematics ;a series of monographs and textbooks ; v 1. . Subjects--Topical Terms: Differential equations, Partial.Mathematical physics. Dewey Class. No.: 517.38