Klуmуk A. U. 1966. “Expansion of a Direct Product of Irreducible Representations of Semisimple Lee Algebras into Irreducible Representations ”. Ukrains’kyi Matematychnyi Zhurnal 18 (5), 19-22. https://umj.imath.kiev.ua/index.php/umj/article/view/8437.