@article{JRAM_1987__381_152975,
     author = {Frank Gerth III},
     title = {Densities for 3-class ranks in certain cubic extensions.},
     journal = {Journal f\"ur die reine und angewandte Mathematik},
     pages = {161--180},
     publisher = {mathdoc},
     volume = {381},
     year = {1987},
     zbl = {0622.12008},
     url = {http://geodesic.mathdoc.fr/item/JRAM_1987__381_152975/}
}