@article{1183485275, author = {Walsh, J. L.}, title = {A generalization of normal congruences of circles}, journal = {Bull. Amer. Math. Soc.}, volume = {28}, number = {9}, year = {1922}, pages = { 456-462}, language = {en}, url = {http://dml.mathdoc.fr/item/1183485275} }
Walsh, J. L. A generalization of normal congruences of circles. Bull. Amer. Math. Soc., Tome 28 (1922) no. 9, pp. 456-462. http://gdmltest.u-ga.fr/item/1183485275/