Dairy science : its principles and practice / by W. E. Petersen ; Edited by R. W. Gregory. Petersen, William Earl, Gregory, R. W. ed. Dairying. Dairy cattle. SF239 .P43 1950 637 PED Includes bibliographical references and index. Philadelphia : Lippincott, 1950. 1950. 1950 Text viii, 679 p. : eng Lippincott's Agricultural Science Series