1. M. Armony, Dynamic routing in large-scale service systems with heterogenous servers, Working Paper, NYU (2004).
2. F. de Véricourt and Y.-P. Zhou, Managing response time and service quality in a call allocation problem, Forthcoming Operations Research (2004).
3. B. Hajek, Optimal control of two interacting service stations, IEEE Transactions on Automatic Control 29 (1984) 491–499.
4. G. Koole, A simple proof of the optimality of a threshold policy in a two-server queueing system, Systems & Control Letters 26 (1995) 301–303.
5. R. Larsen, Control of multiple exponential servers with application to computer systems, Ph.D. Dissertation, Department of Computer Science, University of Maryland, College Park, 1981.