Hamerla, A., Gawron, J., Szydłowski, R. ., Bodera, M. ., Porwolik, H. ., Hamerla, D., Czarnecki, B. ., Kaźmierska, A. ., & Grajcarek, Łukasz . (2026). THE EFFECT OF EXCESSIVE SMARTPHONE USE ON MENTAL WELLBEING, SLEEP QUALITY AND ACTIVE LIFESTYLE BEHAVIOURS. International Journal of Innovative Technologies in Social Science, 2(2(50). https://doi.org/10.31435/ijitss.2(50).2026.4759