共 4 条
[1]
CLARK JW, 1955, W VIRGINIA U BUSINES, V4
[2]
GOULD R, 1960, EVANSTON NW U STUDIE, V5, P96
[3]
Isard W, 1953, AM ECON REV, V43, P167
[4]
TAAFFE EJ, 1956, GEOGRAPHICAL REV, V46, P222