@article{ASNSP_1966_3_20_2_421_0,
     author = {Schechter, Martin},
     title = {Nonlocal elliptic boundary value problems},
     journal = {Annali della Scuola Normale Superiore di Pisa - Scienze Fisiche e Matematiche},
     pages = {421--441},
     publisher = {Scuola normale superiore},
     volume = {Ser. 3, 20},
     number = {2},
     year = {1966},
     mrnumber = {197987},
     zbl = {0152.11005},
     language = {en},
     url = {http://www.numdam.org/item/ASNSP_1966_3_20_2_421_0/}
}