Calamba, I., et al. “The Effects of Classroom Environment on Academic Performance of Grade 1 Pupils at NHC Elementary School”. Ascendens Asia Singapore – Bestlink College of the Philippines Journal of Multidisciplinary Research, vol. 1, no. 1, Apr. 2019, https://ojs.aaresearchindex.com/index.php/aasgbcpjmra/article/view/1197.