Filippidou Χ., Loupos Δ., Zafireiadis Σ. and Barkoukis Β. (2014) “Intensity and Direction of Precompetitive Anxiety: A Study of the Individual Zones of Optimal Functioning Theory in Swimming”, Inquiries in Physical Education and Sport, 12(2), pp. 90–100. doi: 10.26253/heal.uth.ojs.ispe.2014.1422.