Power sources involving ~ 300W PEMFC fuel cell stacks cooled by different media Magdalena Dudek, Andrzej Raźniak, Bartłomiej Lis, Michał Kawalec, Mariusz Krauz and Tadeusz Wójcik E3S Web Conf., 14 (2017) 01042 Published online: 15 March 2017 DOI: 10.1051/e3sconf/20171401042