Voir la notice de l'article provenant de la source Czech Digital Mathematics Library
@article{CMUC_1967__8_1_a11, author = {Vop\v{e}nka, Petr}, title = {General theory of $\nabla$-models}, journal = {Commentationes Mathematicae Universitatis Carolinae}, pages = {145--170}, publisher = {mathdoc}, volume = {08}, number = {1}, year = {1967}, mrnumber = {0214460}, zbl = {0162.01701}, language = {en}, url = {http://geodesic.mathdoc.fr/item/CMUC_1967__8_1_a11/} }
Vopěnka, Petr. General theory of $\nabla$-models. Commentationes Mathematicae Universitatis Carolinae, Tome 08 (1967) no. 1, pp. 145-170. http://geodesic.mathdoc.fr/item/CMUC_1967__8_1_a11/