Rubber : botany, production, and utilization / by Loren G. Polhamus. Polhamus, Loren G. (Loren George), 1895- Rubber. SB290 .P6 634.9856 POR Includes bibliographical references and index. London ; L. Hill , New York : Interscience Publishers, 1962. 1962. 1962 Text xvii, 449 p. : eng World crops books