@incollection{AST_1985__131__255_0,
     author = {Unterberger, Andr\'e},
     title = {L'op\'erateur de {Laplace-Beltrami} du demi-plan et les quantifications lin\'eaire et projective de $SL(2, \mathbb{R})$},
     booktitle = {Colloque en l'honneur de Laurent Schwartz - Volume 1},
     series = {Ast\'erisque},
     pages = {255--275},
     publisher = {Soci\'et\'e math\'ematique de France},
     number = {131},
     year = {1985},
     zbl = {0592.35119},
     mrnumber = {816751},
     language = {fr},
     url = {http://www.numdam.org/item/AST_1985__131__255_0/}
}