Oscar Castillo Luis T. Aguilar Selene Cardenas Fuzzy Logic Tracking Control for Unicycle Mobile Robots. 73-77 2006 13 Engineering Letters 2 db/journals/engl/engl13.html#CastilloAC06 http://www.engineeringletters.com/issues_v13/issue_2/EL_13_2_4.pdf