Voir la notice de l'article provenant de la source Math-Net.Ru
@article{DE_1989_25_7_a21, author = {E. V. Ferapontov}, title = {Reciprocal transformations and their invariants}, journal = {Differencialʹnye uravneni\^a}, pages = {1256--1265}, publisher = {mathdoc}, volume = {25}, number = {7}, year = {1989}, language = {ru}, url = {http://geodesic.mathdoc.fr/item/DE_1989_25_7_a21/} }
E. V. Ferapontov. Reciprocal transformations and their invariants. Differencialʹnye uravneniâ, Tome 25 (1989) no. 7, pp. 1256-1265. http://geodesic.mathdoc.fr/item/DE_1989_25_7_a21/