Andrew Fernando Pakpahan; Adhi Prasetio; Edi Surya Negara; Kasta Gurning; Risanti Febrine Ropita Situmorang; Tasnim Tasnim; Parlin Dony Sipayung; Ayudia Popy Sesilia; Puspita Puji Rahayu; Bonaraja Purba; Muhammad Chaerul; Ika Yuniwati; Valentine Siagian, “Metodologi Penelitian Ilmiah,” Yayasan Kita Menulis, 2021.