Hadijah, M. 2018. Implementation Of Direct Learning Model In Group To Improve Mathematics Achievement In Fifth Grade Students At Sdn 06 Perawang Barat In Academic Year 2012/2013. Jurnal Ilmiah Pendidikan Scholastic. 1, 3 (Oct. 2018), 71–78. DOI:https://doi.org/10.36057/jips.v1i3.148.