Tsonev, Yuliyan, and Milen Sotirov. Gamification in Education as a Way for Improving Student Knowledge and Productivity In 11th International Scientific Conference "Digital Economy and Blockchain Technologies". Varna, 2018.

Tsonev, Yuliyan, and Milen Sotirov. Implementation of Gamification in the University Classrooms In Seventh national conference ?E-learning in higher education?. Sofia, 2018.