@book{SB_1980-1981__23_,
     author = {Collectif},
     title = {S\'eminaire {Bourbaki} : vol. 1980/81, expos\'es 561-578},
     series = {S\'eminaire Bourbaki},
     publisher = {Springer-Verlag},
     number = {23},
     year = {1981},
     url = {http://archive.numdam.org/item/SB_1980-1981__23_/}
}