@article{AMI_2001_28_a9,
     author = {G\'abor Nyul},
     title = {Power integral bases in mixed biquadratic number fields},
     journal = {Annales mathematicae et informaticae},
     pages = {79--86},
     year = {2001},
     volume = {28},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/AMI_2001_28_a9/}
}