Sidarta, Nuryani, Angela BM Tulaar, Amendi Nasution, and Suryanto Suryanto. “Validity and Reliability of Preschool Language Scale 4 for Measuring Language Development in Children 48-59 Months of Age”. Universa Medicina 27, no. 4 (December 26, 2008): 174–182. Accessed April 20, 2024. https://univmed.org/ejurnal/index.php/medicina/article/view/287.