Nelson, Alfred L. Differential equations / Alfred L.Nelson, Karl W. Folley and Max Coral - Boston : D. C. Heath and Company. c1952. - x,,,299 p. : ill. ; 22 cm. Includes index. english LCCN: 56005113 Subjects--Topical Terms: Differential equations. LC Class. No.: QA372 / .R4 1956 Dewey Class. No.: 517.38/NED