Hong Liu Haodi Feng Daming Zhu Junfeng Luan Parameterized computational complexity of control problems in voting systems. 2746-2753 2009 410 Theor. Comput. Sci. 27-29 http://dx.doi.org/10.1016/j.tcs.2009.04.004 db/journals/tcs/tcs410.html#LiuFZL09