Voir la notice de l'article provenant de la source European Digital Mathematics Library
@article{MOMA_1991__111_1_178511, author = {Gerold Wagner}, title = {On {Averaging} {Sets.}}, journal = {Monatshefte f\"ur Mathematik}, pages = {69--78}, publisher = {mathdoc}, volume = {111}, number = {1}, year = {1991}, zbl = {0721.65011}, url = {http://geodesic.mathdoc.fr/item/MOMA_1991__111_1_178511/} }
Gerold Wagner. On Averaging Sets.. Monatshefte für Mathematik, Tome 111 (1991) no. 1, pp. 69-78. http://geodesic.mathdoc.fr/item/MOMA_1991__111_1_178511/