@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}, year = {1969}, publisher = {Gauthier-Villars}, volume = {10}, number = {3}, mrnumber = {249060}, language = {en}, url = {https://www.numdam.org/item/AIHPA_1969__10_3_247_0/} }