@article{10_4064_aa_35_4_385_394,
     author = {Kiyoaki Iimura},
     title = {Dihedral extensions of {Q} of degree 21 which contain {non-Galois} extensions with class number not divisible by l},
     journal = {Acta Arithmetica},
     pages = {385--394},
     publisher = {mathdoc},
     volume = {35},
     number = {4},
     year = {1979},
     doi = {10.4064/aa-35-4-385-394},
     language = {en},
     url = {http://geodesic.mathdoc.fr/articles/10.4064/aa-35-4-385-394/}
}