@article{JRAM_1977__295_151917,
     author = {Manohar L. Madan and Daniel J. Madden},
     title = {Note on class groups of algebraic function fields.},
     journal = {Journal f\"ur die reine und angewandte Mathematik},
     pages = {57--60},
     year = {1977},
     volume = {295},
     zbl = {0355.12011},
     url = {http://geodesic.mathdoc.fr/item/JRAM_1977__295_151917/}
}