@article{JRAM_1971__247_151099,
     author = {Makoto Ishida},
     title = {On algebraic number fields with even class numbers.},
     journal = {Journal f\"ur die reine und angewandte Mathematik},
     pages = {118--122},
     publisher = {mathdoc},
     volume = {247},
     year = {1971},
     zbl = {0212.08004},
     url = {http://geodesic.mathdoc.fr/item/JRAM_1971__247_151099/}
}