Lubis, F., M. A. Nasution, A. Fitri, K. S. Rizwinie, J. Sihaloho, R. A. A. Pasaribu, S. Salsabila, and J. A. Siregar. “Factors Influencing Students’ Difficulties in Using Formal Indonesian Language in The Campus Environment”. EDUCTUM: Journal Research, vol. 2, no. 6, Nov. 2023, pp. 155-8, doi:10.56495/ejr.v2i6.405.