“Differences in Mathematics and Science Achievement by Grade 5 and Grade 8 Student Economic Status: A Multiyear, Statewide Study” (2017) Global Journal of Human-Social Science, 17(H5), pp. 15–26. Available at: https://socialscienceresearch.org/index.php/GJHSS/article/view/2332 (Accessed: 6 August 2026).