@article{MAN_1975__217_162777,
     author = {Heinrich Lang},
     title = {Eine {Invariante} modulo 8 von {Geschlechtern} in reellquadratischen {Zahlk\"orpern.}},
     journal = {Mathematische Annalen},
     pages = {263--266},
     publisher = {mathdoc},
     volume = {217},
     year = {1975},
     zbl = {0297.12005},
     url = {http://geodesic.mathdoc.fr/item/MAN_1975__217_162777/}
}