Butzho, R. L., "Plastic Sheet Forming", Reinhold Plastic Application Series.
2.
Adkins, J. E., and Rivlin, R. S., "Large Elastic Deformation of Isotropic Materials ", J. of Physical Soc., 5/ 1952.
3.
Benning, C. J., and Nutter, J. I., "Filled Polyethylene Foams", Preprints 22nd. Annual Technical Conference, SPE, Montreal, Canada, March 7-11, 1966.
4.
Lasman, H. R., "Foaming Agents For Polyolefins", SPE Journal, 18, 1184-91 (1962).
5.
Benning, C. J., "Polyethylene Foam I-Modified PE Foam Systems." J. Cell. Plas. Vol. 3, No. 2, pg. 62-72, Feb., 1967 .
6.
Benning, C. J., "Polyethylene Foam II-Mechanical Properties of Polyethylene Foams Prepared at High and Low Rates of Expansion." J. Cell. Plas. Vol. 3, No. 3, pg. 125-137, March, 1967.
7.
Rubens, L. C., et al, U.S. Patent 3,067,147 "Process for foaming and extruding polyethylene using Freon as a foaming agent".
8.
Gent, A. N., and Thomas, A. G., 7th Annual Technical Conference Proceedings, Cellular Plastics Division, SPI, New York City, New York, April, 1966.
9.
Hansen, R. H., "Production of fine cells in the Extrusion of Foams", SPE Journal, 18, 77-82 (1962).
10.
Hansen, R. H. and Martin, W. M., "Novel Methods for the production of foamed polymers." I&EC, Prod. Res. Dev.3, No. 2, 137-141 (June, 1964).