Abdulwahed M. Abbas Edward P. K. Tsang Constraint-Based Timetabling-A Case Study. 67-72 2001 conf/aiccsa/2001 AICCSA http://csdl.computer.org/comp/proceedings/aiccsa/2001/1165/00/11650067abs.htm db/conf/aiccsa/aiccsa2001.html#AbbasT01