Higgins, R., and A. Lastovetsky,  "Scheduling for Heterogeneous Networks of Computers with Persistent Fluctuation of Load",  Parallel Computing: Current & Future Issues of High-End Computing, Proceedings of the International Conference ParCo 2005, vol. 33, Malaga, Spain, John von Neumann Institute for Computing, Julich, pp. 171-178, 13-16 Sept 2005, 2006.