@article{1183531491, author = {Ordman, Edward T.}, title = {Subgroups of amalgamated free products}, journal = {Bull. Amer. Math. Soc.}, volume = {76}, number = {4}, year = {1970}, pages = { 358-360}, language = {en}, url = {http://dml.mathdoc.fr/item/1183531491} }
Ordman, Edward T. Subgroups of amalgamated free products. Bull. Amer. Math. Soc., Tome 76 (1970) no. 4, pp. 358-360. http://gdmltest.u-ga.fr/item/1183531491/