de Vries, C.A. Employment for millions of smallfarmers in the tropics : sericulture, bee-keeping and mushroom growing / C.A. de Vries - Amsterdam : RTI , 1977 - 56p. : ill. ; 25 cm. - Bulletin . Includes bibliographical references and index. Subjects--Topical Terms: Agriculture Dewey Class. No.: 638.2 / VRI