Conormal problem of higher-order parabolic systems
  The paper is a comprehensive study of the $L_p$ and the Schauder estimates for higher-order divergence type parabolic systems with discontinuous coefficients in the half space and cylindrical domains with conormal derivative boundary condition. For the $L_p$ estimates, we assume that the leading coefficients are only bounded measurable in the $t$ variable and $VMO$ with respect to $x$. We also prove the Schauder estimates in two situations: the coefficients are H\"older continuous only in the $x$ variable; the coefficients are H\"older continuous in both variables. 
Hongjie Dong and Hong Zhang
math.AP