@article{AIHPA_1971__15_1_1_0,
     author = {Edwards, C. M.},
     title = {Sets of simple observables in the operational approach to quantum theory},
     journal = {Annales de l'I.H.P. Physique th\'eorique},
     pages = {1--14},
     publisher = {Gauthier-Villars},
     volume = {15},
     number = {1},
     year = {1971},
     mrnumber = {288555},
     zbl = {0222.46043},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/AIHPA_1971__15_1_1_0/}
}