Research in Sport and Exercise Psychology Between 2003 and 2013 : an Analysis of the English-Speaking Publication Trends Before the Field's 50th Anniversary - Németh, Lilla (Eötvös Loránd University (Hongria). Institute of Health Promotion and Sport Sciences) ; Vega Marcos, Ricardo de la (Universidad Autónoma de Madrid) ; Szabo, Attila (Eötvös Loránd University (Hongria). Institute of Health Promotion and Sport Sciences)