MathSciDoc: An Archive for Mathematician ∫

@inproceedings{a.1895über,
  title={Über die Anzahl der Classen binärer quadratischer formen von negativer Determinante},
  author={A. Hurwitz},
  url={http://archive.ymsc.tsinghua.edu.cn/pacm_paperurl/20170108203000241866017},
  booktitle={Acta Mathematica},
  volume={19},
  number={1},
  pages={351-384},
  year={1895},
}