Apushkinskaya D.E. Holder estimates of solutions to degenerate Venttsel' boundary value problems for parabolic and elliptic equations of nondivergent form / D.E.Apushkinskaya,А.И.Назаров, 1997. - 16 p. - Текст : непосредственный.
Apushkinskaya D.E. Gradient estimates for solutions of stationary degenerate Venttsel' problems. 1, 1997. - 24 p. - Текст : непосредственный.
Apushkinskaya D.E. Gradient estimates for solutions of stationary degenerate Venttsel' problems. 2, 1998. - 24 p. - Текст : непосредственный.