Coba jelasin Lihat juga dari Jejak ekologi dalam bahasa melayu dong

Hari Lajak Bumi dahulu juga dipanggil Hari Hutang Ekologi

Perakaunan pelepasan gas rumah hijau

Senarai negara mengikut jejak ekologi

Rees, W. E. and M. Wackernagel (1994) Ecological footprints and appropriated carrying capacity: Measuring the natural capital requirements of the human economy, in Jansson, A. et al. Investing in Natural Capital: The Ecological Economics Approach to Sustainability. Washington D.C.:Island Press.

Lenzen, M. and Murray, S. A. 2003. The Ecological Footprint – Issues and Trends. ISA Research Paper 01-03

Chambers, N., Simmons, C. and Wackernagel, M. (2000), Sharing Nature's Interest: Ecological Footprints as an Indicator of Sustainability. Earthscan, London  (see also http://www.ecologicalfootprint.com)