7William E R. Revisiting carrying capacity: Area-based indicators of sustainability [EB/OL]. http://www.dieoff, com/page110, htm, 1997-09-27.
8Wackernagel M, Onisto L, Bello P, et al. National natural capitalaccounting with the ecological footprint concept[J].Ecological Economics, 1999,29(3) : 375-3901.
9Fu Bojie, Gulinck H. Land evaluation in area of severe erosion; the loess plateau of China[J]. Land Degradation & Rehabilitation, 1994,5 ( 1 ) : 33-40.
10Stomph T J, Fresco L O, Keulen H. Land use system evaluation., concepts and methodology[J].Agricultural Systems, 1994,44 : 243-255.