共 11 条
[2]
BOWSER W. E., 1933, CANADIAN JOUR RES, V8, P73
[4]
Crafts AS, 1939, J AGRIC RES, V58, P0637
[5]
GRAU FV, 1933, US GOLF ASS GREEN SE, V13, P154
[6]
HAINES W. E., 1933, JOUR AMER SOC AGRON, V25, P181
[8]
KARRER AMH, 1940, USDA TECH B, V648
[9]
KIESSELBACH TA, 1934, NEBRASKA AGR EXP STA, V287
[10]
Offord HR, 1931, J AGRIC RES, V43, P0791