Nursaba, Siti, et al. “Athlete Self-Confidence Questionnaire (ASQ): A Valid and Reliable Instrument for Measuring Athlete Self-Confidence”. Jorpres (Jurnal Olahraga Prestasi), vol. 20, no. 2, Sept. 2024, pp. 10-15, doi:10.21831/jorpres.v20i2.73311.