@Misc{polymake,
  author = 	 "Ewgenij Gawrilow and Michael Joswig",
  title = 	 {polymake},
  howpublished = {\URL{http://www.math.tu-berlin.de/polymake/}}
}


@Misc{polyhedral,
  author = 	 {Dutour Sikiric, Mathieu},
  title =        {Polyhedral},
  howpublished = {\URL{http://www.liga.ens.fr/~dutour/Polyhedral/index.html}}
}



@Misc{hap,
  author = 	 {Graham Ellis},
  title =        {HAP},
  howpublished = {\URL{http://hamilton.nuigalway.ie/Hap/www/}}
}


@Misc{cryst,
  author = 	 "Bettina Eick and Franz G\"ahler and Werner Nickel",
  title =        {cryst},
  howpublished = {\URL{http://www.gap-system.org/Packages/cryst.html}}
}