@article{ASNSP_1976_4_3_1_121_0,
     author = {Mc Connell, William H.},
     title = {On the approximation of elliptic operators with discontinuous coefficients},
     journal = {Annali della Scuola Normale Superiore di Pisa - Classe di Scienze},
     pages = {121--137},
     publisher = {Scuola normale superiore},
     volume = {Ser. 4, 3},
     number = {1},
     year = {1976},
     mrnumber = {406020},
     zbl = {0339.35006},
     language = {en},
     url = {http://archive.numdam.org/item/ASNSP_1976_4_3_1_121_0/}
}