Cristina Bazgan Miklos Santha Zsolt Tuza Efficient Approximation Algorithms for the SUBSET-SUMS EQUALITY Problem. 160-170 2002 64 J. Comput. Syst. Sci. 2 http://dx.doi.org/10.1006/jcss.2001.1784 db/journals/jcss/jcss64.html#BazganST02