Marios Mavronicolas Loizos Michael Paul G. Spirakis Computing on a partially eponymous ring. 595-613 2009 410 Theor. Comput. Sci. 6-7 http://dx.doi.org/10.1016/j.tcs.2008.10.010 db/journals/tcs/tcs410.html#MavronicolasMS09