1. H. Blades, US Patent 3,767,756 (1973).
2. T. Hayshi, T. Hiraj, and A. Nakajima, Am. Chem. Soc. Polym. Prepr.,20, No. 1, 53–56 (1979).
3. V. N. Kiya-Oglu, G. A. Belinskii, et al., Khim. Volokna, No. 4, 20–22 (1992).
4. G. A. Belinskii, Candidate Dissertation, All-Russian Scientific-Research of Synthetic Fibres-Planning, Mytishchi (1988).
5. T. Kaneda, S. Ishikawa, et al., Makromol. Chem.,183, 417–457 (1981).