1. Meadows, D.H. et al. 'The Limits to Growth' (Pan Books, England)
2. Perspectives in recycling;Perbix;Reclamation Industries,1972
3. Energy, recycling and growth;Chapman;Reclamation Industries International,1974
4. Methods for producing secondary copper;Spendlove;US Bureau of Mines Information Circular 8002,1961
5. Bureau Internationale de la Recuperation (BIR) (Metall-Verlag Gmbh, 1 Berlin 33)