Shantanu Das Paola Flocchini Shay Kutten Amiya Nayak Nicola Santoro 34-48 2007 385 Theor. Comput. Sci. 1-3 http://dx.doi.org/10.1016/j.tcs.2007.05.011 db/journals/tcs/tcs385.html#DasFKNS07