@incollection{AST_1978__51__415_0,
     author = {Sigmund, Karl},
     title = { Affine transformations on the space of probability measures},
     booktitle = {Syst\`emes dynamiques III - Varsovie},
     series = {Ast\'erisque},
     pages = {415--427},
     publisher = {Soci\'et\'e math\'ematique de France},
     number = {51},
     year = {1978},
     mrnumber = {480946},
     zbl = {0385.28010},
     language = {en},
     url = {http://archive.numdam.org/item/AST_1978__51__415_0/}
}