共 12 条
[1]
BRANSTETTER BB, 1927, MISSOURI AGR EXP STN, V113
[2]
EIBEN GJ, 1967, THESIS IOWA STATE U
[3]
HOLBERT JR, 1925, ILL AGR EXP STN B, V225
[5]
KOEHLER B, 1925, ILL AGR EXP STN B, V266