@article{JMPA_1949_9_28__321_0,
     author = {Dixmier, J.},
     title = {Sur les vari\'et\'es $J$ d{\textquoteright}un espace de {Hilbert}},
     journal = {Journal de Math\'ematiques Pures et Appliqu\'ees},
     pages = {321--358},
     volume = {9e s{\'e}rie, 28},
     year = {1949},
     zbl = {0041.44309},
     mrnumber = {32938},
     language = {fr},
     url = {http://www.numdam.org/item/JMPA_1949_9_28__321_0/}
}