1. United, Nations,United Nations. Report of the World Commission on Environment and Development, Our Common Future, 1987.
2. U.N.,UN. World population prospects: the 2015 revision. Population Division of the Department of Economic and Social Affairs of the United Nations Secretariat, New York. 2015.
3. Hildebrandt, S.,Hildebrandt, S. Bæredygtig global udvikling, FN's verdensmål i et dansk perspektiv, Jurist- og Økonomiforbundets forlag, 2016, figure 12.3.
4. Hildebrandt, S.,Hildebrandt, S. Bæredygtig global udvikling, FN's verdensmål i et dansk perspektiv, Jurist- og Økonomiforbundets forlag, 2016, page 301.
5. Roodman, D.M., Lenssen, N.,Roodman, D. M. and Lenssen, N. (1994). Our buildings, ourselves. World Watch, 7(6):21.