@article{M2AN_1993__27_5_565_0,
     author = {Vanmaele, M. and \v{Z}en{\'\i}\v{s}ek, A.},
     title = {External finite element approximations of eigenvalue problems},
     journal = {ESAIM: Mod\'elisation math\'ematique et analyse num\'erique},
     pages = {565--589},
     publisher = {AFCET - Gauthier-Villars},
     address = {Paris},
     volume = {27},
     number = {5},
     year = {1993},
     mrnumber = {1239816},
     zbl = {0792.65086},
     language = {en},
     url = {http://www.numdam.org/item/M2AN_1993__27_5_565_0/}
}