Nadia Creignou Phokion G. Kolaitis Bruno Zanuttini Structure identification of Boolean relations and plain bases for co-clones. 1103-1115 2008 74 J. Comput. Syst. Sci. 7 http://dx.doi.org/10.1016/j.jcss.2008.02.005 db/journals/jcss/jcss74.html#CreignouKZ08