Freiberg, Phillip. “Advancing SDG 4: Digital Textbooks for Russian Pupils (Grades 6-11): Bridging the Digital Divide - From Digital Inequality to Digital Maturity”. NIDA Case Research Journal 17, no. 1 (June 30, 2025): 62–104. accessed September 28, 2026. https://so04.tci-thaijo.org/index.php/NCRJ/article/view/273314.