Paray Theo Lonando, P. T. L., A. Firdaus, and R. Hakim. “Designing A Web Information System In The Guest Book Using The Waterfall Method At Ikest Muhammadiyah Palembang”. Journal Health Applied Science and Technology, vol. 2, no. 2, Sept. 2024, pp. 173-7, doi:10.52523/jhast.v2i2.67.