Yu Lei Raghu Kacker D. Richard Kuhn Vadim Okun James Lawrence IPOG/IPOG-D: efficient test generation for multi-way combinatorial testing. 125-148 2008 18 Softw. Test., Verif. Reliab. 3 http://dx.doi.org/10.1002/stvr.381 db/journals/stvr/stvr18.html#LeiKKOL08