共 19 条
[1]
CARLEY DH, 1973, 149 GA AGR EXP STA R
[4]
FRIEDRICH CJ, 1928, A WEBERS THEORY LOCA
[5]
HALLBERG MC, 1972, 728 PENN AGR EXP STA
[6]
HARDY WE, 1973, 24 AUB U DEP AGR EC
[7]
HARDY WE, 1972, THESIS VIRGINIA POLY
[8]
HUIE JM, 1970, EC397 PURD U IND COO
[10]
MUHICH AJ, 1970, 1968 NATIONAL SURVEY, P7