Stefan Porschen Bert Randerath Ewald Speckenmeyer Exact 3-satisfiability is decidable in time O(2<sup>0.16254<i>n</i></sup>). 173-193 2005 43 Ann. Math. Artif. Intell. 1 http://www.springerlink.com/index/10.1007/s10472-005-0428-2 db/journals/amai/amai43.html#PorschenRS05