Hasibuan, H. A., and I. Irvan. “Ethnomathematics Exploration of Making Traditional Ombus-Ombus Cake Typical of North Tapanuli As a Source of Mathematics Learning”. Mathline : Jurnal Matematika Dan Pendidikan Matematika, vol. 10, no. 1, Feb. 2025, pp. 85-95, doi:10.31943/mathline.v10i1.717.