Kelsey, Lincoln David. Cooperative extension work / Lincoln David Kelsey with the collaboration of Cannon Chiles Hearne. - 3rd edition. - Ithaca, New York : Comstock Publishing Associates, c1967. - 490 pages : Illustrations ; 24 cm. Subjects--Topical Terms: Agricultural extension work. LC Class. No.: S544 / .K4 1963 Dewey Class. No.: 630.717