@article{10_4064_aa_73_2_147_188,
     author = {Charles Helou},
     title = {Norm residue symbol and cyclotomic units},
     journal = {Acta Arithmetica},
     pages = {147--188},
     year = {1995},
     volume = {73},
     number = {2},
     doi = {10.4064/aa-73-2-147-188},
     language = {en},
     url = {http://geodesic.mathdoc.fr/articles/10.4064/aa-73-2-147-188/}
}