Grigoris Daskalogrigorakis, Salva Kirakosian, Angelos Marinakis, Vaggelis Nikolidakis, Ioanna Pateraki, Aristomenis Antoniadis, Katerina Mania: G-Code Machina: A Serious Game for G-code and CNC Machine Operation Training. EDUCON 2021: 1434-1442