AN ELEMENTARY TREATISE ON DIFFERENTIAL EQUATIONS AND THEIR APPLICATIONS by H. T. H. PIAGGIO, M. A., D. Sc. PROFESSOR OF MATHEMATICS, UNIVERSITY COLLEGE, NOTTINGHAM SENIOR SCHOLAR OF ST. JOHNS COLLEGE, CAMBRIDGE LONDON G. BELL AND SONS, LTD, 1949 First published May 1920. Reprinted 1921, 1924, 1925, 1926 Revised and Enlarged Edition 1922 reprinted 1929, 1931, 1933, 1937, 1959, 1940, 1911, 1942, 1943, 1944, 1945, 1946, 1949. PRINTED IN GREAT BRITAIN...