Al Zahra, Yenni, et al. “Analisis Kadar Surfaktan Anionik Pada Air Sungai Negara Menggunakan Metode Spektrofotometri Visible”. Innovative: Journal Of Social Science Research, vol. 3, no. 6, Dec. 2023, pp. 8067-73, https://j-innovative.org/index.php/Innovative/article/view/7395.