1. Altinkemer, K., & Gavish, B. (1988). Heuristics with constant error guarantees for the design of tree networks. Management Science, 34(3), 331–341.
2. Arkin, E. M., Guttmann-Beck, N., & Hassin, R. (2012). The (k, k)-capacitated spanning tree problem. Discrete Optimization, 9(4), 258–266.
3. Berkelaar, M., Eikland, K., & Notebaert, P. (2010). lp_solve 5.5.2.0. http://lpsolve.sourceforge.net/5.5/ . Accessed 2014-3-2.
4. Cormen, T. H., Stein, C., Rivest, R. L., & Leiserson, C. E. (2001). Introduction to algorithms (2nd ed.). New York: McGraw-Hill Higher Education.
5. Diestel, R. (2006). Graph theory (3rd ed.). Berlin: Springer.