@article{AIHPA_1967__6_4_267_0,
     author = {Testard, D.},
     title = {Alg\`ebre de covariance},
     journal = {Annales de l'I.H.P. Physique th\'eorique},
     pages = {267--297},
     publisher = {Gauthier-Villars},
     volume = {6},
     number = {4},
     year = {1967},
     mrnumber = {218907},
     zbl = {0152.46306},
     language = {fr},
     url = {http://geodesic.mathdoc.fr/item/AIHPA_1967__6_4_267_0/}
}