E-learning and games 12th International Conference, Edutainment 2018, Xi'an, China, June 28–30, 2018 : proceedings - Rhalibi, Abdennour el 1964-; Pan, Zhigeng; Jin, Haiyan; Ding, Dandan; Navarro-Newball, Andrés Adolfo; Wang, Yinghui (Springer, 2019)