Vannisa Rachmatika, Siti, and Sri Sumarti. “Effectiveness of Health Communication via WhatsApp on Adolescents’ Knowledge Change Regarding Gastritis Risk”. Impact : Multidisciplinary Journal 1, no. 01 (July 1, 2025): 26–33. Accessed August 30, 2025. https://journal.takaza.id/index.php/impact/article/view/134.