TY  - BOOK
AU  - Martin, John H.
TI  - Principles of field crop production 
AV  - SB187 .U6M3 1967 1393
PY  - 1967///
CY  - New York 
PB  - The Macmillan co.
KW  - Field crop production
N1  - Includes bibliographical references and index
ER  -