Debashis Bera Madhumangal Pal Tapan Kumar Pal An Efficient Algorithm to Generate all Maximal Cliques on Trapezoid Graphs. 1057-1065 2002 79 Int. J. Comput. Math. 10 http://taylorandfrancis.metapress.com/openurl.asp?genre=article&issn=0020-7160&volume=79&issue=10&spage=1057 db/journals/ijcm/ijcm79.html#BeraPP02