@book{AST_1981__81__1_0,
     author = {Buser, Peter and Karcher, Hermann},
     title = {Gromov's almost flat manifolds},
     series = {Ast\'erisque},
     publisher = {Soci\'et\'e math\'ematique de France},
     number = {81},
     year = {1981},
     mrnumber = {619537},
     zbl = {0459.53031},
     language = {en},
     url = {http://archive.numdam.org/item/AST_1981__81__1_0/}
}