Volume optimization of gear trains with spur gears using genetic algorithm Nenad Marjanović, Nenad Kostić, Nenad Petrović, Mirko Blagojević and Miloš Matejić MATEC Web Conf., 121 (2017) 01007 Published online: 09 August 2017 DOI: 10.1051/matecconf/201712101007