Ahmad Al Zahrani Andrew Bailey Guoyuan Fu Jia Di Glitch-free design for multi-threshold CMOS NCL circuits. 215-220 2009 ACM Great Lakes Symposium on VLSI http://doi.acm.org/10.1145/1531542.1531596 conf/glvlsi/2009 db/conf/glvlsi/glvlsi2009.html#ZahraniBFD09