1. P. D. Mar’yanchuk, Izvestiya VUZov. Fizika, No. 1, 122–124 (1984).
2. P. D. Maryanchuk and N. P. Gavaleshko, Izv. Akad. Nauk USSR, Neorg. Mater., 23, No.8, 1271–1274 (1987).
3. P. D. Mar’yanchuk, Izv. Vyssh. Uchebn. Zaved. Fiz., No. 9, 117–119 (1993).
4. P. D. Mar'yanchuk and N. P. Gavaleshko, Russ. Phys. J., 34, No. 4, 312–315 (1991).
5. P. D. Mar'yanchuk and N. P. Gavaleshko, Russ. Phys. J., 30, No. 11, 903–906 (1987).