Dr. Fereddy Siagian, M. Th., M.M, et al. “KEPEMIMPINAN, ETOS KERJA DAN KETERAMPILAN KERJA TIM (Leadership and Team Working Skills) ”. YPAD Penerbit, vol. 1, no. 1, June 2024, https://journal.yayasanpad.org/index.php/ypadbook/article/view/102.