Day-as, M. T. U., and P. T. B. Damoco. “Grade 4 Bilingual Mathematics Workbook”. Ascendens Asia Singapore – Union Christian College Philippines Journal of Multidisciplinary Research Abstracts, vol. 5, no. 1, Sept. 2023, p. 46, https://ojs.aaresearchindex.com/index.php/aasguccphjmra/article/view/12579.