%0 Journal Article
%T A centennial of the Zaremba--Hopf--Oleinik Lemma
%A Alexander I. Nazarov
%J Mathematics
%D 2010
%I arXiv
%X We discuss the problem how "bad" may be lower-order coefficients in elliptic and parabolic second order equations to ensure the Hopf--Oleinik Lemma for solutions to hold true. We also touch the gradient estimates for solutions at the boundary.
%U http://arxiv.org/abs/1101.0164v2