J. B. Mueller and S. J. Thomas: Decentralized Formation Flying Control in a Multiple-Team Hierarchy, Annals of the New York Academy of Sciences 1065.1, pp. 112-138, 2005
Schaub H, Vadali SR, Junkins JL, Alfriend KT: Spacecraft formation flying control using mean orbit elements, Journal of the Astronautical Sciences, Jan 1, 48(1), pp. 69-87, 2000