@article{10_4064_aa136_2_3,
     author = {Xuejun Guo},
     title = {On the 4-rank of tame kernels of quadratic
 number fields},
     journal = {Acta Arithmetica},
     pages = {135--149},
     publisher = {mathdoc},
     volume = {136},
     number = {2},
     year = {2009},
     doi = {10.4064/aa136-2-3},
     language = {en},
     url = {http://geodesic.mathdoc.fr/articles/10.4064/aa136-2-3/}
}