@article{10_1017_S0017089500003037,
     author = {Cohen, S. D. and Odoni, R. W. K.},
     title = {The {Farey} density of norm subgroups of global fields {(II)}},
     journal = {Glasgow mathematical journal},
     pages = {57--67},
     year = {1977},
     volume = {18},
     number = {1},
     doi = {10.1017/S0017089500003037},
     url = {http://geodesic.mathdoc.fr/articles/10.1017/S0017089500003037/}
}