@article{CM_1984__53_2_133_0,
     author = {Cornell, Gary and Rosen, Michael I.},
     title = {The $\ell $-rank of the real class group of cyclotomic fields},
     journal = {Compositio Mathematica},
     pages = {133--141},
     publisher = {Martinus Nijhoff Publishers},
     volume = {53},
     number = {2},
     year = {1984},
     mrnumber = {766293},
     zbl = {0551.12006},
     language = {en},
     url = {http://www.numdam.org/item/CM_1984__53_2_133_0/}
}