Smart Cities, Green Technologies and Intelligent Transport Systems 8th International Conference, SMARTGREENS 2019, and 5th International Conference, VEHITS 2019, Heraklion, Crete, Greece, May 3–5, 2019, Revised Selected Papers - Helfert, Markus; Klein, Cornel; Donnellan, Brian; Gusikhin, Oleg (Springer International Publishing, 2021)