Tretynyk, V. V. “Hidden Symmetries of the Two-Particle Dirac Equation With Linear Interaction”. Ukrains’kyi Matematychnyi Zhurnal 48, no. 9 (September 25, 1996): 1295–1296. Accessed June 2, 2024. https://umj.imath.kiev.ua/index.php/umj/article/view/5244.