@article{M2AN_1978__12_3_211_0,
     author = {Bercovier, M.},
     title = {Perturbation of mixed variational problems. {Application} to mixed finite element methods},
     journal = {RAIRO. Analyse num\'erique},
     pages = {211--236},
     publisher = {Centrale des revues, Dunod-Gauthier-Villars},
     address = {Montreuil},
     volume = {12},
     number = {3},
     year = {1978},
     mrnumber = {509973},
     zbl = {0428.65059},
     language = {en},
     url = {http://archive.numdam.org/item/M2AN_1978__12_3_211_0/}
}