Kuznetsova, V. (2011). MODEL REPRESENTATIONS OF THE LIE ALGEBRA $[A_2, A_1] = iA_1$ OF LINEAR NON-SELFADJOINT OPERATORS. Ann. Sofia Univ. Fac. Math. And Inf., 100, 93–112. Retrieved from https://ftl5.uni-sofia.bg/index.php/fmi/article/view/248