Husna, Husna, et al. “The Effect of Whatsapp Video-Based Education on Delivery on Knowledge and Attitude of Pregnant Women in Trimester III in The Time of Covid-19 ”. Science Midwifery, vol. 10, no. 2, May 2022, pp. 1065-70, https://midwifery.iocspublisher.org/index.php/midwifery/article/view/443.