T. Sebayang, A. Sinuhaji, T. Bangun, M. Marbun, and A. Sutanto, “The Spectrum of Gastroenteritis at the Pediatric Outpatient Clinic,. Department of Child Health, School of Medicine, University of North Sumatera in 1982”, PI, vol. 28, no. 1-2, pp. 1-13, Jul. 2019.