@article{10_4064_aa_22_4_449_459,
     author = {Maurice Craig},
     title = {A type of class group for imaginary quadratic fields},
     journal = {Acta Arithmetica},
     pages = {449--459},
     publisher = {mathdoc},
     volume = {22},
     number = {4},
     year = {1972},
     doi = {10.4064/aa-22-4-449-459},
     language = {en},
     url = {http://geodesic.mathdoc.fr/articles/10.4064/aa-22-4-449-459/}
}