Darweesh, S. A., Hammodi, A. S., & Mahmmod, R. M. (2016). A new Spectrophotometric Method For The Determination of La (III) With 3-Hydroxy -4-(2-hydroxyPhenyl azo) Naphthalene -1- Sulfonic Acid. Ibn AL-Haitham Journal For Pure and Applied Sciences, 24(1). https://jih.uobaghdad.edu.iq/index.php/j/article/view/869