Asterina, R., S. Siregar, B. Madiyono, and B. Supriyatno. “Clinical Manifestations of Childhood Asthma Persisting until the Age of Seven”. Paediatrica Indonesiana, Vol. 44, no. 1, Oct. 2016, pp. 1-6, doi:10.14238/pi44.1.2004.1-6.