1. M. Szwarc, Nature 78, 1168 (1956).
2. J. P. Kennedy, J. Polym. Sci., Part A: Polym. Chem. 37, 2285 (1999).
3. A. V. Yakimansky, Polym. Sci., Ser. C 47, 1 (2005).
4. A. M. Kaplan, B. La Serna, I. L. Stoyachenko, E. I. Shklyarova, V. B. Golubev, V. P. Zubov, V. A. Kabanov, and V. I. Gol’danskii, Dokl. Akad. Nauk SSSR 224, 829 (1975).
5. A. M. Kaplan, I. L. Stoyachenko, V. B. Golubev, and V. I. Gol’danskii, Vysokomol. Soedin., Ser. B 17, 259 (1975).