@article{ASENS_2015__48_3_607_0,
     author = {Bekka, Bachir and Guivarc'h, Yves},
     title = {On the spectral theory of groups  of affine transformations  of compact nilmanifolds},
     journal = {Annales scientifiques de l'\'Ecole Normale Sup\'erieure},
     pages = {607--645},
     publisher = {Soci\'et\'e Math\'ematique de France. Tous droits r\'eserv\'es},
     volume = {Ser. 4, 48},
     number = {3},
     year = {2015},
     doi = {10.24033/asens.2253},
     mrnumber = {3377054},
     zbl = {1335.22009},
     language = {en},
     url = {http://www.numdam.org/articles/10.24033/asens.2253/}
}