T. N. Du, H. A. . Nguyen, V. H. . Pham, D. D. . Nguyen, and . D. T. . Mai, “The Quality Assurance of Early Childhood Education in Preschools in the Mekong Delta, Vietnam: Integrating the CIPO and PDCA Frameworks”, IJLTER, vol. 25, no. 7, pp. 326–351, Jul. 2026.