共 7 条
[1]
DUMENIL L, 1952, IOWA AGRIC EXP STN A, P114
[2]
EARLEY EB, 1948, 3 AM SEED TRAD ASS H, P84
[3]
GOODALL DW, 1947, 17 IMP BUR HORT PLAN
[4]
HEADY EO, 1955, 424 IOW AGR EXP STN