1. Hilyard, N. C., Young, J.: Introduction. In: Mechanics of Cellular Plastics Hilyard. N.C. (ed.). London: Applied Sci. Publ. 1982, pp. 1–26
2. Semerdjiev, S.: Introduction to Structural Foam. Brookfield Center: Soc. Plastics Engineers, 1982
3. Eckardt, H.: Ind. Prod. Eng. No 2, 170 (1980); Plast. World 38, 66 (1980)
4. Meyer, W.: J. Cell. Plast. 15, 91 (1979)
5. N.N.: Brit. Plast. Rubber No 6, 41 (1979)