Yarni, Asna. 2017. “Improving Competitive Appreciative Value With Competitive Learning Model and Cooperative Learning for Mathematics in Grade Sixth of Elementary School no.01 Koto Pulai Kecamatan Lengayang”. Jurnal Ilmiah Pendidikan Scholastic 1 (1):164-75. https://doi.org/10.36057/jips.v1i1.296.