1. Gotch, T. M. (1979). Plast. Rubb. Int., 4 (3), 119–24.
2. Elastomer Chemical Corporation US Patent 2 666 036; British Patents 767 465; 770237.
3. Ward, D. W. (1969–70). Modern Plastics Encyclopedia, pp. 256–9.
4. Dennis, I., US Patent 2 763 475.
5. Fuchs, O., Heckalt, F., and Herz, A. (1965). Kunststoffe. 55 (9), 717–23.