Farzan Fallah Stan Y. Liao Srinivas Devadas Solving covering problems using LPR-based lower bounds. 9-17 2000 8 IEEE Trans. VLSI Syst. 1 http://doi.ieeecomputersociety.org/10.1109/92.820757 db/journals/tvlsi/tvlsi8.html#FallahLD00