Samoilenko , Y.S. and Shulman , V.S. (1991) “Representations of correlations of the $і [A, B] = f(A) + g(B)$ type”, Ukrains’kyi Matematychnyi Zhurnal, 43(1), pp. 110–114. Available at: https://umj.imath.kiev.ua/index.php/umj/article/view/9313 (Accessed: 6 December 2025).