Y. Xu, H. Vatankhah. Simspark: An open source robot simulator developed by the robocup community. Robot Soccer World Cup, 2013 Jun 24 (pp. 632-639). Springer, Berlin, Heidelberg.
J. Boedecker, M. Asada. Simspark - concepts and application in the robocup 3d soccer simulation league. Autonomous Robots, 174, Nov. 2008. [PDF]
O. Obst and M. Rollmann. Spark - A generic simulator for physical multi-agent simulations. Computer Systems Science and Engineering, 20(5), Sep. 2005. [PDF]