ATABEKYAN, V. S. ABOUT THE CONSTRUCTION OF DEFINING RELATIONS IN FREE PERIODIC GROUPS. Proceedings of the YSU A: Physical and Mathematical Sciences, Yerevan, Armenia, v. 37, n. 3 (202), p. 30–35, 2003. DOI: 10.46991/PYSUA.2003.37.3.030. Disponível em: https://journals.ysu.am/index.php/proceedings-phys-math/article/view/vol37_no3_2003_pp030-035. Acesso em: 22 jan. 2026.