VERBA, I. I.; KOLODY, I. M. An A Priori Estimate for the Modulus of Continuity of a Generalized Solution of a Parabolic Equation of Divergent Form with Degeneracy. Ukrains’kyi Matematychnyi Zhurnal, v. 53, n. 2, p. 190-202, 25 Feb. 2001.