Masood, Hajra, and Lal Khan. “STUDIESON SODIUM SULPHIDE PREPAREDFROM SODIUM SULPHATE”. Biological Sciences - PJSIR 47, no. 2 (April 26, 2004): 163–165. Accessed April 16, 2025. https://v2.pjsir.org/index.php/biological-sciences/article/view/1490.