1. Algorithmic solution of the change-making problem;Chang;J. Assoc. Comput. Mach.,1970
2. Computers and Intractability;Garey,1979
3. Optimal bounds for the change-making problem;Kozen;Theor. Comput. Sci.,1994
4. G.S. Lueker, Two NP-complete problems in nonnegative integer programming, Report No. 178, Computer Science Laboratory, Princeton University, 1975.