1. Bakhir, V.M. and Zadorozhnyi, Yu.G. Russian Patent 2078737, IPC6 C 02 F 1/461/, publ. May 10, 1997, Byull. No. 10.
2. Ramazanov, Z.D. and Miroshnik, E.S., Russian Patent 2084408, IPC6 C o2 F 1/461, publ. July 20, 1997, Byull. No. 12.
3. Popov, A.Yu. and Popov, D.A., Russian Patent 2132821, IPC7 C 02 F 1/461/, publ. July 10, 1999, Byull. No. 19.
4. Bakhir, V.M., Zadorozhnyi, Yu.G., and Panicheva, S.A., Russian Patent 2204530, publ. May 20, 2003, Byull. No. 14.
5. Rogov, V.M. and Filipchuk, V.L., Khimiya i Tekhnologiya Vody, 1983, vol. 5., no. 1, pp. 45–49.