3Wackernagel M,et al.Ecological footprints of nations:how much nature do they use? How much nature do they have?[R].Commissioned by the earth council for the Rio +5 Forum.International Council for Local Environmental initiatives,Toronto,1997.
4Rees W E.Revisiting Carrying Capacity:Area-Based indicators of Sustainability[J].Population and Environment,1996,17 (3):195-218.