Wolfgang W. Bein Shahram Latifi Linda Morales Ivan Hal Sudborough Bounding the Size of k-Tuple Covers. 1-8 2009 HICSS http://dx.doi.org/10.1109/HICSS.2009.92 conf/hicss/2009 db/conf/hicss/hicss2009.html#BeinLMS09