1. The obstacle problem for the biharmonic operator.;Caffarelli;Ann SCM, Sup, Pisa,1979
2. Error estimates of two nonconforming finite elements for the obstacle problem.;Lieheng;JCM,1986
3. Some strongly discontinuous nonconforming finite element approximations of a fourth order variational inequality with displacement obstacle.;Lieheng;Acta Numerical Mathematica,1990
4. Finite element approximations and iterative solutions of a fourth order elliptic variational inequality.;Glowinski;IMA J Numer Anal,1984
5. Quasi-conforming elements in finite element analysis.;Limin;Jour Dalian Institute of Technology,1989