"Urethane Energy Absorbers for Automobile Bumpers" Peter A. Weller, (September, 1972).
2.
"Suitability of Semi-rigid Urethane Foam to Automotive Bumper Applications ," Mobay Chemical Company, (April, 1971 ).
3.
"Plastics for Automobile Safety Bumpers," Ulrich Knipp, Presented in Montreal, Society of Plastics Industry, (1972).
4.
"Flexible Urethane Foams Changing Technology of the 70's," Howard G. Ostfield, Presented at the Plastics Institute of America, (July, 1971).
5.
"Microcellular Elastomeric Urethanes," G. F. Baumann, Rubber Chemistry & Technology, Volume 45, No. 5, (September, 1972).
6.
"Impact Testing of High Density Semi-rigid Urethane Foam for Automotive Bumper Applications," F. J. Limbert and W. J. Persin, Automotive Engineering Congress, (January 10-14, 1972).
