共 6 条
[1]
ABROL IP, 1972, CSSRI1 DIV SOILS AGR
[3]
SINGH AN, 1982, 17TH P INT S REM SEN, P787
[5]
WHITCOMB E, 1971, AGRARIAN CONDITIONS, V1, P80
[6]
1975, USDA AGR HDB, V436