@article{M2AN_1985__19_3_397_0,
     author = {J. Douglas, Jr. and Milner, F. A.},
     title = {Interior and superconvergence estimates for mixed methods for second order elliptic problems},
     journal = {ESAIM: Mod\'elisation math\'ematique et analyse num\'erique},
     pages = {397--428},
     publisher = {AFCET - Gauthier-Villars},
     address = {Paris},
     volume = {19},
     number = {3},
     year = {1985},
     mrnumber = {807324},
     zbl = {0613.65110},
     language = {en},
     url = {http://archive.numdam.org/item/M2AN_1985__19_3_397_0/}
}