Gottschalk, Louis Reichenthal, 1899-1975. Understanding history : a primer of historical method / Louis Gottschalk. - [1st ed.] - New York : Knopf, c1950. - xix, 298, vi p. ; 20 cm. Includes index. Subjects--Topical Terms: Historiography. LC Class. No.: 901 Dewey Class. No.: 901