共 20 条
[3]
Gray R. W., 1972, Food Research Institute Studies in Agricultural Economics, Trade, and Development, V11, P313
[4]
HEIFNER RJ, 1972, AGR ECON RES, V25, P25
[5]
HELMERS GA, 1977, W J AGR EC, V2, P157
[6]
HOLT MT, 1984, AUG AAEA ANN M ITH
[8]
IKERD JE, 1978, FUTURES TRADING SEMI, V4, P1