Dave Levin Randolph Baden Cristian Lumezanu Neil Spring Bobby Bhattacharjee Motivating participation in internet routing overlays. 91-96 2008 NetEcon http://doi.acm.org/10.1145/1403027.1403048 conf/sigcomm/2008netecon db/conf/sigcomm/netecon2008.html#LevinBLSB08