Oktay, A., Doğan, H., Özcan, Z. Çiğdem, Dönmez, Özlem, & Özdemir, H. (2021). Investigation of academic achievement, self-efficacy and psychological resilience of sixth grade students starting primary school at different ages. Pegem Journal of Education and Instruction, 11(1), 187–216. https://doi.org/10.14527/pegegog.2021.006