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@article{CM_1935__1__254_0, author = {Baer, Reinhold}, title = {Der {Kern,} eine charakteristische {Untergruppe}}, journal = {Compositio Mathematica}, pages = {254--283}, publisher = {Johnson Reprint Corporation}, volume = {1}, year = {1935}, zbl = {0009.15504}, language = {de}, url = {http://geodesic.mathdoc.fr/item/CM_1935__1__254_0/} }
Baer, Reinhold. Der Kern, eine charakteristische Untergruppe. Compositio Mathematica, Tome 1 (1935), pp. 254-283. http://geodesic.mathdoc.fr/item/CM_1935__1__254_0/