共 10 条
[5]
KIESSELBACH TA, 1949, U NEBRASKA COLL AGR, V161
[6]
Randolph LF, 1936, J AGRIC RES, V53, P0881
[7]
SASS JOHN E., 1951, IOWA STATE COLL JOUR SCI, V25, P509
[8]
STEIN OL, 1949, P MINNESOTA ACAD SCI, V17, P98
[9]
STEIN OL, 1952, THESIS U MINNESOTA
[10]
WANG KW, 1939, THESIS U MINNESOTA