James C. Beyer David Hung-Chang Du Ewa Kusmierek Improved n 1-cover discovery using perimeter coverage information. 175-190 2008 3 IJSNet 3 http://www.inderscience.com/search/index.php?action=record&rec_id=18480&prevQuery=&ps=10&m=or db/journals/ijsnet/ijsnet3.html#BeyerDK08