REFERENCES
1. Biryuk, E. Art gymnastics. Sofia: Narodna prosveta Publ. House, 1984, pp. 3-19 (in Bulg.).
2. Bobrova, G. Art gymnastics in sports schools. Sofia: Meditsina i fizkultura, 1977, pp. 9-53 (in Bulg.).
3. Dimitrova, S. The art how to win. Sofia: Meditsina i fizkultura, 1988, 115 p. (in Bulg.).
4. Gigova, M., L. Tsvetkova, T. Shishkova. Bulgarian art gymnastics. Sofia: Meditsina i fizkultura, 1982, p. 81 (in Bulg.).
5. Kechedzhieva, L., M. Vankova, M. Chipriyanova. Early training in art gymnastics. Sofia: Meditsina i fizkultura, 1983, pp. 5-37 (in Bulg.).
6. Milev, N., E. Kotov. Bulgarian gymnastics. Sofia: Meditsina i fizkultura, 1974, 111 p. (in Bulg.).
7. Nedyalkova, G. Art gymnastics for the smallest children. Sofia: Meditsina i fizkultura, 1987, p. 86 (in Bulg.).
8. Pirovska, M., M. Nikolova, G. Nedyalkova, R. Popova. Art gymnastics in schools. Methodical handbook. Sofia: Narodna prosveta Publ. House, 1980, p. 159 (in Bulg.).