@article{AIHPA_1978__28_2_187_0,
     author = {Fannes, M.},
     title = {The entropy density of quasi-free states for a continuous boson system},
     journal = {Annales de l'I.H.P. Physique th\'eorique},
     pages = {187--196},
     publisher = {Gauthier-Villars},
     volume = {28},
     number = {2},
     year = {1978},
     mrnumber = {496234},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/AIHPA_1978__28_2_187_0/}
}