Situmeang, M., R. J. BR. Silalahi, and R. Purba. “Morphological Processes Found in Umpasa and Umpama of Tobanese "Pesta Na Monding””. Jurnal Ilmiah Wahana Pendidikan, Vol. 7, no. 8, Dec. 2021, pp. 558-65, doi:10.5281/zenodo.5793124.