Khamaruddin, S., L. Rahmah, and T. Prasetyorini. “The Relationship of House Environmental Sanitation With Infection of Muhamadiyah Elementry School Students in Deli Serdang District”. Asian Journal of Applied Sciences, vol. 7, no. 6, Dec. 2019, doi:10.24203/ajas.v7i6.6022.