@article{AFST_2010_6_19_S1_143_0,
     author = {Madden, James J.},
     title = {On $f$-rings that are not formally real},
     journal = {Annales de la Facult\'e des sciences de Toulouse : Math\'ematiques},
     pages = {143--157},
     publisher = {Universit\'e Paul Sabatier, Institut de math\'ematiques},
     address = {Toulouse},
     volume = {Ser. 6, 19},
     number = {S1},
     year = {2010},
     doi = {10.5802/afst.1279},
     zbl = {1213.06013},
     mrnumber = {2675725},
     language = {en},
     url = {http://www.numdam.org/articles/10.5802/afst.1279/}
}