共 134 条
[62]
GUSSOW A, 1979, P OUR NATIONAL LANDS, P6
[65]
Harris G., 1980, LEISURE SCI, V3, P349, DOI [DOI 10.1080/01490408009512943, 10.1080/01490408009512943]
[67]
HULL RB, 1989, USDA SOUTHE, V52, P485