3Wackernagel M, Onisto L, Bello P, et al. National natural Capital ac- counting with ecological footprints concept E J 1. Ecological Econom- ics, 1999,29:375 - 390.
4Wackernagcl M, Onisto L, Bello P, el al. Ecological Footprints of Na- tionsE R~. Commissioned by the Earth Council For the Rio + Forum. Toronto : International council for Local Environmental Initiatives, 1997: 4-21.
