Nasser R. Sabar Masri Ayob Graham Kendall Rong Qu Roulette Wheel Graph Colouring for Solving Examination Timetabling Problems. 463-470 2009 COCOA http://dx.doi.org/10.1007/978-3-642-02026-1_44 conf/cocoa/2009 db/conf/cocoa/cocoa2009.html#SabarAKQ09