@article{10_4171_dm_238,
     author = {Dimitar P. Jetchev and William A. Stein},
     title = {Visibility of the {Shafarevich-Tate} group at higher level},
     journal = {Documenta mathematica},
     pages = {673--696},
     year = {2007},
     volume = {12},
     doi = {10.4171/dm/238},
     url = {http://geodesic.mathdoc.fr/articles/10.4171/dm/238/}
}