共 29 条
[4]
Dallenbarger L. E., 1992, Agribusiness (New York), V8, P35, DOI 10.1002/1520-6297(199201)8:1<
[5]
35::AID-AGR2720080104>
[6]
3.0.CO
[7]
2-V
[9]
HECKMAN JJ, 1976, ANN ECON SOC MEAS, V5, P475
[10]
HUFFMAN WE, 1988, AGR PRODUCTIVITY MEA