Kotvytskiy, A.T., Bronza, S.D. і Shablenko, V.Y. 2017. CORRELATION OF THE NUMBER OF IMAGES OF AN N-POINT GRAVITATIONAL LENS AND THE NUMBER OF SOLUTIONS OF ITS SYSTEM. Одеські астрономічні публікації. 30, (Лис 2017), 35–37. DOI:https://doi.org/10.18524/1810-4215.2017.30.114229.