@article{MZ_1978__159_172645,
     author = {Peter Walters},
     title = {Equilibrium {States} for {{\ss}-Transformations} and {Related} {Transformations.}},
     journal = {Mathematische Zeitschrift},
     pages = {65--88},
     year = {1978},
     volume = {159},
     zbl = {0364.28016},
     url = {http://geodesic.mathdoc.fr/item/MZ_1978__159_172645/}
}