Korah, F. J. F., and V. G. Sengkey. “Personality and Proficiency: Investigating How Extrovert-Introvert Traits Relate to English Speaking Performance”. FOSTER: Journal of English Language Teaching, Vol. 6, no. 2, Apr. 2025, pp. 66-75, doi:10.24256/foster-jelt.v6i2.242.