1. C. Barraque, J. Burriat, and J. M. Rovel, FR Patent No. 7834555 (Degremont, 1978).
2. S. L. Gromov and A. A. Panteleev, “Counterflow lonite Regeneration Technologies for Water Treatment: Part 1,” Teploenergetika, No. 8, 34–38 (2006) [Therm. Eng., No. 8 (2006)].
3. S. Evans, UK Patent No. 1471162 (1977).
4. S. Evans, UK Patent No. 1501308 (1977).
5. S. Evans, J. H. Hootsen, and A-J. P. Van Eck, UK Patent No. 1539161 (1978).