1. A. G. Sukiasyan, A. Ts. Malkhasyan, G. S. Grigoryan, and R. E. Sagatelyan, RF Pat. No. 92010089 (1996).
2. JP Appl. No. 5993771 (1984).
3. JP Appl. No. 5989377 (1984).
4. JP Appl. No. 6443586 (1989).
5. V. V. Polikarpov, V. I. Lukhovitskii, and N. S. Savinova, RF Patent No. 98111371 (2000).