Vamsi Vankamamidi Fabrizio Lombardi Design of defect tolerant tile-based QCA circuits. 237-242 2008 ACM Great Lakes Symposium on VLSI http://doi.acm.org/10.1145/1366110.1366169 conf/glvlsi/2008 db/conf/glvlsi/glvlsi2008.html#VankamamidiL08