1. OR–Library. Available at the web address http://mscmga.ms.ic.ac.uk/info.html .
2. Tsplib. Available at the web address http://www.iwr.uni-heidelberg.de/groups/comopt/software/TSPLIB95/ .
3. Avella, P., Sassano, A.: On the p-median polytope. Mathematical Programming, 89, 395–411 (2001)
4. Barahona, F., Anbil, R.: The volume algorithm: producing primal solutions with a subgradient algorithm. Mathematical Programming, 87, 385–399 (2000)
5. Barahona, F., Chudak, F.: Solving large scale uncapacitated facility location problems. In: Pardalos, P. (ed.), Approximation and Complexity in Numerical Optimization, pp. 48–62, 2000