1. Alonso, A.: Error estimators for a mixed method. Numer. Math. 74(4), 385–395 (1996)
2. Arnold, D.N., Brezzi, F., Douglas, J.: PEERS: a new mixed finite element method for plane elasticity. Jpn. J. Appl. Math. 1, 347–367 (1984)
3. Arnold, D.N., Falk, R.S., Winther, R.: Differential complexes and stability of finite element methods. II: the elasticity complex. In: Arnold, D.N., Bochev, P., Lehoucq, R., Nicolaides, R., Shashkov, M. (eds.) Compatible Spatial Discretizations. IMA Volumes in Mathematics and Its Applications, vol. 142, pp. 47–67. Springer, New York (2005)
4. Arnold, D.N., Falk, R.S., Winther, R.: Finite element exterior calculus, homological techniques, and applications. Acta Numer. 15, 1–155 (2006)
5. Arnold, D.N., Falk, R.S., Winther, R.: Mixed finite element methods for linear elasticity with weakly imposed symmetry. Math. Comput. 76(260), 1699–1723 (2007)