共 8 条
[1]
FLEMING WE, 1936, 237 USDA
[2]
FLEMING WE, 1936, 401 USDA
[3]
GOODHUE LYLE D., 1936, JOUR ECON ENT, V29, P580, DOI 10.1093/jee/29.3.580
[5]
GUY HG, 1937, DEL AG EXP STA B, V206
[7]
SAFRO VI, 1929, 152 N J DEP AG
[8]
SMITH LB, 1923, USDA B, V1154