@article{AIHPA_1967__6_4_299_0,
     author = {Robinson, Derek W. and Ruelle, David},
     title = {Extremal invariant states},
     journal = {Annales de l'I.H.P. Physique th\'eorique},
     pages = {299--310},
     publisher = {Gauthier-Villars},
     volume = {6},
     number = {4},
     year = {1967},
     mrnumber = {217609},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/AIHPA_1967__6_4_299_0/}
}