Strongly nonlinear elliptic equations and systems are investigated under mi
xed boundary value conditions. It is supposed that the domain is a multidim
ensional polyhedral domain. Global regularity results of \del u\(sigma) (si
gma greater than or equal to 1) are proven, in particular, W-s,W-p (Omega)-
regularity (s < 1/2) of \del u\ and \del u\(2).