Voir la notice de l'article provenant de la source Novi sad journal of mathematics website
@article{NSJOM_2011_41_2a_9, author = {Sorasak Leeratanavalee}, title = {Idempotent {Elements} of $WP_G(2, 2)\cup \{\sigma_{id}\}$}, journal = {Novi Sad Journal of Mathematics}, pages = {99-109}, publisher = {mathdoc}, volume = {41}, number = {2}, year = {2011}, url = {http://geodesic.mathdoc.fr/item/NSJOM_2011_41_2a_9/} }
Sorasak Leeratanavalee. Idempotent Elements of $WP_G(2, 2)\cup \{\sigma_{id}\}$. Novi Sad Journal of Mathematics, Tome 41 (2011) no. 2. http://geodesic.mathdoc.fr/item/NSJOM_2011_41_2a_9/