Nonstationary Venttsel problems with discontinuous data

The paper deals with Venttsel boundary problems for second-order linear and quasilinear parabolic operators with discontinuousprincipal coefficients. These are supposed to be functions of vanishing mean oscillationwith respect to the space variables, while only measurabilityis required in the time-variable. We derive aprioriestimates in composite Sobolev spaces for the strong solutions, and develop maximal regularity and strong solvability theory for such problems