Toghanyan, V. H. “SUBDIRECT INDECOMPOSABLE PARTIALLY COMMUTATIVE, NORMAL AND QUASI NORMAL ALGEBRAS”. Proceedings of the YSU A: Physical and Mathematical Sciences 37, no. 2 (201) (June 3, 2003): 30–37. Accessed March 11, 2026. https://journals.ysu.am/proceedings-phys-math/article/view/vol37_no2_2003_pp030-037.