TY  - BOOK
AU  - Grigg,D.B.
TI  - The agricultural systems of the world: an evolutionary approach 
SN  - 0521202698
AV  - S494 .5 .S95 G75 1979
PY  - 1979///
CY  - London
PB  - Cambridge University Press
KW  - Agricultural systems
N1  - Includes bibliographical references and index
ER  -