Oktaria, Tri, et al. “PENGEMBANGAN LKS BERBASIS APOS BERBANTUAN MICROSOFT EXCEL PADA POKOK BAHASAN PROGRAM LINIER DI SMK”. Jurnal Pendidikan Matematika RAFA, vol. 2, no. 2, May 2017, pp. 229-48, https://jurnal.radenfatah.ac.id/index.php/jpmrafa/article/view/1250.