TY  - PRO
AU  - Collins,M.P.
TI  - Productivity maintenance research and research deterioration:  Concepts and evidence
PY  - 1992///
KW  - Mexico
KW  - Nepal
KW  - Production factors
KW  - Productivity
KW  - AGROVOC
KW  - Wheat
N1  - Tables, graphs, references p. 13
ER  -