Deviation of level lines and their orthogonal trajectories under univalent convex maps of the unit disc
English version (Springer): Ukrainian Mathematical Journal 41 (1989), no. 9, pp 1088-1092.
Citation Example: Butenko A. A., Sizhuk P. I. Deviation of level lines and their orthogonal trajectories under univalent convex maps of the unit disc // Ukr. Mat. Zh. - 1989. - 41, № 9. - pp. 1263–1267.
Full text