F. Lubis, K. Nathanael, N. D. Samosir, S. G. B. Regar, W. A. Maharani, and Z. Khairunnisha, “Language Proficiency in Standard and Non-Standard Language Among Students of The Faculty of Economics, State University of Medan”, EJR, vol. 2, no. 6, pp. 164–167, Nov. 2023.