1. T. Graham, Philos. Trans. R. Soc. London, A 151, 682 (1861).
2. G. R. Kroit, Usp. Khim. 9, 682 (1940).
3. S. P. Papkov, V. A. Kargin, and Z. A. Rogovin, Zh. Fiz. Khim. 10, 156 (1937).
4. V. A. Kargin, S. P. Papkov, and Z. A. Rogovin, Zh. Fiz. Khim. 12, 206 (1939).
5. S. P. Papkov, Gel-Like State of Polymers (Mir, Moscow, 1974) [in Russian].