1. and Eds., ?Plastic Foams,? Vol. I. Part II, p. 967, Marcel Dekker, Inc., N.Y. (1973).
2. Emerson & Cuming, Inc., Canton, Massachusetts (USA), ?Ecco Reflector & Lens Index,? Technical Bulletin No. 12-2-1 (July 1963).
3. ?Properties of Foamed Dylite Polystyrene,? Sinclair-Koppers Co. Bull. 9-273, Pittsburgh, Pa. (1969).
4. and British Patent No. 605, 863 (1948).
5. The free volume of polystyrene