Voir la notice de l'article provenant de la source European Digital Mathematics Library
@article{MOMA_1970__74_177515, author = {Gert Sabidussi}, title = {Idempotency of {Circuit-induced} {Exchange} {Operators.}}, journal = {Monatshefte f\"ur Mathematik}, pages = {330--335}, publisher = {mathdoc}, volume = {74}, year = {1970}, zbl = {0239.05130}, url = {http://geodesic.mathdoc.fr/item/MOMA_1970__74_177515/} }
Gert Sabidussi. Idempotency of Circuit-induced Exchange Operators.. Monatshefte für Mathematik, Tome 74 (1970), pp. 330-335. http://geodesic.mathdoc.fr/item/MOMA_1970__74_177515/