Saputra, Haris, Sulaiman Yusuf, Noval Azis, Amir Syarifuddin, and Bistok Saing. 2001. “Development of Children of 2 – 3 Years Old from Pre-Prosperous Family and Prosperous Family Stage II”. Paediatrica Indonesiana 41 (3-4), 100-105. https://doi.org/10.14238/pi41.2.2001.100-105.