Ambarita, E, R Sibarani, D Widayati, and E Setia. “Nominal Word Formations in Toba Batak Language: A Study of Generative Morphology”. KnE Social Sciences 3, no. 4 (April 19, 2018): 306–320. Accessed August 6, 2020. https://knepublishing.com/index.php/KnE-Social/article/view/1942.