1. Arnold, D.N., Brezzi, F.: Mixed and nonconforming finite element methods: implementation, postprocessing, and error estimates. M2AN,19, 7–32 (1985)
2. Arnold, D.N., Brezzi, F., Douglas, J., Jr.: Peers: a new mixed finite element for plane elasticity. Japan J. Appl. Math.1, 347–367 (1984)
3. Brezzi, F., Douglas, J., Jr., Marini, L.D.: Two families of mixed finite elements for second order elliptic problems. Numer. Math.47, 217–235 (1985)
4. Brezzi, F., Douglas, J., Jr., Marini, L.D.: Variable degree mixed methods for secod order elliptic problems. Mat. Apl. Comput.4, 19–34 (1985)
5. Brown, D.C.: Alternating-direction iterative schemes for mixed finite element methods for second order elliptic problems. Thesis, University of Chicago 1982