Prosenjit Bose Luc Devroye William S. Evans David G. Kirkpatrick On the Spanning Ratio of Gabriel Graphs and beta-Skeletons. 412-427 2006 20 SIAM J. Discrete Math. 2 http://dx.doi.org/10.1137/S0895480197318088 db/journals/siamdm/siamdm20.html#BoseDEK06