A. Petrosyan and K. Avetisyan, “WEIGHTED SPACES OF FUNCTIONS HARMONIC IN THE UNIT BALL”, Proc. YSU A: Phys. Math. Sci., vol. 51, no. 1 (242), pp. 3–7, Mar. 2017, doi: 10.46991/PYSU:A/2017.51.1.003.