@article{JRAM_1977__296_151938,
     author = {S.J. Gurak},
     title = {Ideal-theoretic characterization of the relative genus field.},
     journal = {Journal f\"ur die reine und angewandte Mathematik},
     pages = {119--124},
     publisher = {mathdoc},
     volume = {296},
     year = {1977},
     zbl = {0356.12013},
     url = {http://geodesic.mathdoc.fr/item/JRAM_1977__296_151938/}
}