Boundedness of weak solutions of degenerate quasilinear equations with   rough coefficients
  We derive local boundedness estimates for weak solutions of a large class of second order quasilinear equations. The structural assumptions imposed on an equation in the class allow vanishing of the quadratic form associated with its principal part and require no smoothness of its coefficients. The class includes second order linear elliptic equations as studied by D. Gilbarg and N. S. Trudinger [1998] and second order subelliptic linear equations as studied by E. Sawyer and R. L. Wheeden [2006 and 2010]. Our results also extend ones obtained by J. Serrin [1964] concerning local boundedness of weak solutions of quasilinear elliptic equations. 
Dario D. Monticelli, Scott Rodney and Richard L. Wheeden
math.AP