@article{JTNB_2008__20_1_183_0,
     author = {Mazur, Marcin and Ullom, Stephen V.},
     title = {Unit indices and cohomology for biquadratic extensions of imaginary quadratic fields},
     journal = {Journal de th\'eorie des nombres de Bordeaux},
     pages = {183--204},
     publisher = {Universit\'e Bordeaux 1},
     volume = {20},
     number = {1},
     year = {2008},
     doi = {10.5802/jtnb.621},
     mrnumber = {2434163},
     language = {en},
     url = {http://www.numdam.org/articles/10.5802/jtnb.621/}
}