TY  - BOOK
AU  - Anderson Jock R Ed.
AU  -  Hazell Peter B R Ed.
TI  - Variablity in grain yields :  Implications for agri   
U1  - X9(J382).1(X).N8, M9 
PY  - 1989///
CY  - Baltimore
PB  - John Hopkins university press       
KW  - Wheat
N1  - International food policy research institute
ER  -