Dalalyan, S.H. “$S$-UNIVERSALITY IN 2-CATEGORIES”. Proceedings of the YSU A: Physical and Mathematical Sciences 45, no. 2 (225) (April 28, 2011): 39–44. Accessed September 19, 2024. https://pub.ysu.am/index.php/proceedings-phys-math/article/view/vol45_no2_2011_pp039-044.