Yacine Boufkhad Olivier Dubois Length of Prime Implicants and Number of Solutions of Random CNF Formulae. 1-30 1999 215 Theor. Comput. Sci. 1-2 db/journals/tcs/tcs215.html#BoufkhadD99 http://dx.doi.org/10.1016/S0304-3975(95)00184-0