1. G. V. Gens and E. V. Levner. Approximation algorithms for certain universal problems in scheduling theory. Soviet J. of Comp. System Sci., 6:31–36, 1978.
2. Lecture Notes in Control and Information Sciences;G.V. Gens,1980
3. O. H. Ibarra and C. E. Kim. Fast approximation algorithms for the knapsack and sum of subset problems. J. ACM, 22:463–468, 1975.
4. H. Kellerer, R. Mansini, U. Pferschy, and M.G. Speranza. An efficient fully polynomial approximation scheme for the subset-sum problem. Technical report, University of Graz, Department of Business, 1997.
5. E. Lawler. Fast approximation algorithms for knapsack problems. Math. Oper. Res., 4:339–356, 1979.