1. Ahrens, J., 1980. (Milisco Manufacturing Company); Multidensity foam article and method of preparation, US Patent US 4190697 A, February 28th.
2. Auto Alliance, Cars Move America: State of the Auto Industry http://www.autoalliance.org/files/AA_CarsMoveAmerica_Appendix.pdf (Accessed December 5th, 2016).
3. Recycling of waste poly(ethylene terephthalate) with castor oil using microwave heating
4. Energy Performance of Buildings: Energy Efficiency and Built Environment in Temperate Climates,2016
5. Brennan, M. (Texaco, Inc.), 1982. Aromatic polyols made from recycled polyethylene terephthalate waste streams, alkylene glycol and dibasic acid waste streams. U.S. Patent US 4439550 A, November 22nd.