@article{BSMF_1979__107__3_0,
     author = {Berger, Marcel},
     title = {Une in\'egalit\'e universelle pour la premi\`ere valeur propre du laplacien},
     journal = {Bulletin de la Soci\'et\'e Math\'ematique de France},
     pages = {3--9},
     publisher = {Soci\'et\'e math\'ematique de France},
     volume = {107},
     year = {1979},
     doi = {10.24033/bsmf.1881},
     mrnumber = {80f:58046},
     zbl = {0399.35080},
     language = {fr},
     url = {http://archive.numdam.org/articles/10.24033/bsmf.1881/}
}