Voir la notice de l'article provenant de la source Bulgarian Digital Mathematics Library
@article{SMJ2_1999_25_1_a4, author = {Pyrih, Pavel}, title = {On the sense preserving mappings in the {Helm} topology in the plane}, journal = {Serdica Mathematical Journal}, pages = {41--46}, publisher = {mathdoc}, volume = {25}, number = {1}, year = {1999}, language = {en}, url = {http://geodesic.mathdoc.fr/item/SMJ2_1999_25_1_a4/} }
Pyrih, Pavel. On the sense preserving mappings in the Helm topology in the plane. Serdica Mathematical Journal, Tome 25 (1999) no. 1, pp. 41-46. http://geodesic.mathdoc.fr/item/SMJ2_1999_25_1_a4/