Janetria. “Analysis of Ability to Recognize Letters B and D Ages 5 — 6 Years in Private Kindergarten St. Antonius 2 Medan”. Indonesian Journal of Advanced Research 3, no. 2 (February 29, 2024): 261–274. Accessed April 24, 2026. https://journal.formosapublisher.org/index.php/ijar/article/view/8169.