Piotr Berman Marek Karpinski Alex D. Scott Approximation Hardness of Short Symmetric Instances of MAX-3SAT Electronic Colloquium on Computational Complexity (ECCC) 2003 049 db/journals/eccc/eccc10.html#ECCC-TR03-049 http://eccc.hpi-web.de/eccc-reports/2003/TR03-049/index.html