共 14 条
[1]
ADAMS JE, 1937, USDA TECH B, V586
[2]
CARTTER JACKSON L., 1940, SOIL SCI SOC AMER PROC, V5, P125
[3]
COLLINS ER, 1947, 295 AGR EXT SERV CIR
[4]
COLWELL WE, 1944, BETTER CROPS, V28, P23
[5]
COLWELL WE, 1944, BETTER CROPS, V28, P44
[6]
ETHERIDGE WC, 1922, MO AGR EXP STA B, V195
[9]
LANG AL, 1942, ILLINOIS EXT SERV LE
[10]
MACKENZIE AJ, IN PRESS ANAL CHEM