ASTM D3574-81, "Standard Methods of Testing Flexible Cellular Materials-Slab, Bonded and Molded Urethane Foams."
5.
Dwyer, F. J., M. Kaplan, E.L. Piver, Jr. and H. Stone. "Technology of Super Soft Flexible Urethane Foams;' Modern Plastics, 139 (May 1964).
6.
Piperno, A. and J. Wojtasinski. "New Hypersoft Urethane Foams;' Presented at the September 1972 International Cellular Plastics Conference in Montreal.