Voir la notice de l'article provenant de la source European Digital Mathematics Library
@article{MAN_1884__23_157110, author = {Engel}, title = {Zur {Theorie} der {Ber\"uhrangstransformationen.}}, journal = {Mathematische Annalen}, pages = {1--44}, publisher = {mathdoc}, volume = {23}, year = {1884}, url = {http://geodesic.mathdoc.fr/item/MAN_1884__23_157110/} }
Engel. Zur Theorie der Berührangstransformationen.. Mathematische Annalen, Tome 23 (1884), pp. 1-44. http://geodesic.mathdoc.fr/item/MAN_1884__23_157110/