共 6 条
[1]
Martin J. C., 1946, SOIL SCI SOC AMER PROC, V10, P94
[2]
McBeth IG, 1917, J AGRIC RES, V9, P141
[3]
PEECH ML, 1947, USDA757 CIR
[4]
Richards LA, 1947, DIAGNOSIS IMPROVEMEN
[5]
Stanford G., 1947, SOIL SCI SOC AMER PROC, V11, P155
[6]
STANFORD G, 1948, SOIL SCI SOC AM P, V12, P167