ZAKARIA, T. M.; KASIH, J.; HALIM, N.; GUNADI, M. S. Design and Build a Mandarin Course Payment System Using the Waterfall Method. Jurnal Teknik Informatika dan Sistem Informasi, Jakarta, Indonesia, v. 9, n. 1, p. 127 –, 2023. DOI: 10.28932/jutisi.v9i1.5979. Disponível em: https://journal.maranatha.edu/index.php/jutisi/article/view/5979. Acesso em: 4 may. 2024.