@incollection{SB_1980-1981__23__132_0,
     author = {Gallot, Sylvestre},
     title = {Minorations sur le $\lambda _1$ des vari\'et\'es riemanniennes},
     booktitle = {S\'eminaire Bourbaki : vol. 1980/81, expos\'es 561-578},
     series = {S\'eminaire Bourbaki},
     note = {talk:569},
     pages = {132--148},
     publisher = {Springer-Verlag},
     number = {23},
     year = {1981},
     zbl = {0493.53034},
     language = {fr},
     url = {http://www.numdam.org/item/SB_1980-1981__23__132_0/}
}