Sularyo, Titi, Ulynar Marpaung, and Arwin Akib. 1999. “Profile of Mother’s Knowledge and Behavior Toward Stimulation and Their Babies’ Development in an Urban Poor Area in Jakarta”. Paediatrica Indonesiana 39 (9-10), 278-86. https://doi.org/10.14238/pi39.9-10.1999.278-86.