Sukhorolsky , M. A., O. V. Veselovska, and V. V. Dostoina. “Systems of Complex Variable Polynomials Related to Classical Systems of Orthogonal Polynomials”. Ukrains’kyi Matematychnyi Zhurnal, Vol. 73, no. 11, Nov. 2021, pp. 1516 -31, doi:10.37863/umzh.v73i11.6699.