Yulian, E., E. Paryanto, and S. Hapsara. “The Duration of Playing Play Station@ As a Risk Factor of Obesity in School Age Children in Yogyakarta”. Paediatrica Indonesiana, Vol. 48, no. 1, Feb. 2008, pp. 15-7, doi:10.14238/pi48.1.2008.15-7.