@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}} }