@incollection{UBHD-68188665,
  author={Amendola, Luca and Fogli, Simone and Guarnizo, Alejandro and Vollmer, Adrian},
  title={Model-independent constraints on the cosmological anisotropic stress},
  year={2013},
  language={eng},
  note={Gesehen am 10.11.2017},
  booktitle={De.arxiv.org},
}
@article{UBHD-67947049,
  author={Amendola, Luca and Fogli, Simone and Guarnizo, Alejandro and Vollmer, Adrian},
  title={Model-independent constraints on the cosmological anisotropic stress},
  year={2014},
  pages={13 S.},
  language={eng},
  issn={1550-2368 and 1089-4918},
  volume={89(2014},
  journal={Physical review},
  doi={10.1103/PhysRevD.89.063538},
}