I. A. Nababan, A. Sitanggang, S. S. Irwansyah, R. Budiarti, V. S. B. L. Tobing, and L. V. Sitanggang, “English Correspondence: Case Study of English Education Department of University of HKBP Nommensen Students’ Perspective of Cover Letter/Application Letter”, Innovative, vol. 5, no. 3, pp. 498–513, May 2025.