Mathematics of Computation, Vol. 71, No. 240 (Oct., 2002), pp. 1421-1430 (10 pages) Finite element derivative superconvergent points for harmonic functions under local rectangular mesh are ...

This is a preview. Log in through your library . Abstract We give estimates in Lp, 1 < p ≤ 2, for the second order derivatives of the solution to the inhomogeneous Neumann problem in a convex domain.