Hanrahan, Joanna, and Irawan Mangunatmadja. “Intrinsic Risk Factors for Gross Motor Delay in Children Aged 6-24 Months”. Paediatrica Indonesiana 59, no. 1 (February 26, 2019): 27-32. Accessed May 14, 2021. https://www.paediatricaindonesiana.org/index.php/paediatrica-indonesiana/article/view/2029.