@article{AIHPA_1969__10_3_247_0,
     author = {Rocca, F. and Sirugue, M. and Testard, D.},
     title = {Translation invariant quasi-free states and {Bogoliubov} transformations},
     journal = {Annales de l'institut Henri Poincar\'e. Section A, Physique Th\'eorique},
     pages = {247--258},
     publisher = {Gauthier-Villars},
     volume = {10},
     number = {3},
     year = {1969},
     mrnumber = {249060},
     language = {en},
     url = {http://archive.numdam.org/item/AIHPA_1969__10_3_247_0/}
}