@article{701480,
     title = {Locally finitely generated differential spaces of class $C^r$
               },
     booktitle = {Proceedings of the Winter School "Geometry and Physics"},
     series = {GDML\_Books},
     publisher = {Circolo Matematico di Palermo},
     address = {Palermo},
     year = {1991},
     pages = {[57]-66},
     mrnumber = {MR1151892},
     zbl = {0749.58007},
     url = {http://dml.mathdoc.fr/item/701480}
}

Borgiel, Włodzimierz; Buchner, Klaus; Sasin, Wiesław. Locally finitely generated differential spaces of class $C^r$
               , dans Proceedings of the Winter School "Geometry and Physics", GDML_Books,  (1991), pp. [57]-66. http://gdmltest.u-ga.fr/item/701480/