@article{AIHPA_1980__33_4_395_0, author = {Pul\`e, J. V.}, title = {Positive maps of the {CCR} algebra with a finite number of non-zero truncated functions}, journal = {Annales de l'I.H.P. Physique th\'eorique}, pages = {395--408}, publisher = {Gauthier-Villars}, volume = {33}, number = {4}, year = {1980}, mrnumber = {605199}, zbl = {0471.46039}, language = {en}, url = {http://geodesic.mathdoc.fr/item/AIHPA_1980__33_4_395_0/} }