共 21 条
[2]
COMMONER B, 1968, AM ASS ADV SCI
[3]
COMMONER B, 1968, BALANCE NATURE PROVI
[4]
DAWES JH, 1969, AUG ANN M SOIL CONS
[5]
HAAS HJ, 1957, 1164 US DEP AGR TECH
[6]
HEADDEN WP, 1910, 160 COL STAT AGR EXP
[7]
HEADY EO, 1967, PRIMER FOOD AGRICULT, P9
[9]
IBACH DB, 1958, 202 US DEP AGR INF B
[10]
LEGGE RF, 1970, CAN RES DEVELOP, V19