1. “The Green Report”, compiled by a Working Party of the National Association of Attorneys General of the USA, 1990.
2. Standard Practice for Determining Degradation End Point in Degradable Polyethylene and Polypropylene Using a Tensile Test, ASTM Designation D 3826–91.
3. Degradable Materials,: Perspectives, Issues and Opportunities,1990
4. Biodegradable Polymers and Plastics,1992
5. Reference 4, p. 75.