Puspita, T. ., and T. Rismayanti. “The Effectiveness of Education Using WhatsApp About the Importance of Pregnancy Checks for Increasing the Knowledge of Pregnant Women in Karangsinom Village, Tirtamulya District, Karawang Regency in 2023”. International Journal of Health and Pharmaceutical (IJHP), vol. 4, no. 3, Sept. 2024, pp. 531-6, doi:10.51601/ijhp.v4i3.353.