Richie Ricardo, K. Pranata, Jerry Alexander Jenmartin, Ferdy Anthonius, and C. Siregar, “The Importance of Handwashing with Soap for the Health and National Defense Values of Students at Panunggangan 4 Elementary School”, SEHATMAS: Jurnal Ilmiah Kesehatan Masyarakat, vol. 5, no. 1, pp. 100–109, Jan. 2026.