Myungsu Choi Zachary D. Patitz Byoungjae Jin Feng Tao Nohpill Park Minsu Choi Designing layout-timing independent quantum-dot cellular automata (QCA) circuits by global asynchrony. 551-567 2007 53 Journal of Systems Architecture 9 http://dx.doi.org/10.1016/j.sysarc.2006.12.007 db/journals/jsa/jsa53.html#ChoiPJTPC07