@article{CTGDC_1985__26_1_63_0,
     author = {Vale, Maria J.},
     title = {Torsors and special extensions},
     journal = {Cahiers de Topologie et G\'eom\'etrie Diff\'erentielle Cat\'egoriques},
     pages = {63--90},
     publisher = {Dunod \'editeur, publi\'e avec le concours du CNRS},
     volume = {26},
     number = {1},
     year = {1985},
     mrnumber = {794417},
     zbl = {0578.18010},
     language = {en},
     url = {http://www.numdam.org/item/CTGDC_1985__26_1_63_0/}
}