Phillips, C. W. et. al."A Rating Method for Refrigerated Trailer Bodies Hauling Perishable Foods" . Marketing Research Report No. 433. September, 1960.
2.
Heffner, G. R., "Development of the Foamed-In-Place Urethane Reefer."Plastics Foam Insulation Conference S. P. I., April 26, 1962.
3.
Hilado, C. J., "Effect of Accelerated and Environmental Aging on Rigid Urethane Foam."1966 Polymer Conference Series, Wayne State University , Detroit, Michigan.
4.
Siren, R. L., Markets and Economics of Cellular Plastics, International Foamed Plastic Markets & Directory , 1966-67 Ed., Technomic Publishing Co., Inc.