@article{JRAM_1972__252_151185,
     author = {Manohar L. Madan},
     title = {Class groups of global fields.},
     journal = {Journal f\"ur die reine und angewandte Mathematik},
     pages = {171--177},
     year = {1972},
     volume = {252},
     zbl = {0229.12012},
     url = {http://geodesic.mathdoc.fr/item/JRAM_1972__252_151185/}
}