“?SPECTROPHOTOMETRIC DETERMINATION OF TITANIUM AND IRON-ApPLICATION TO CHERAT VOLCANIC ASH, N.W.F.P”. (1998) Biological Sciences - PJSIR, 41(4), pp. 217–220. Available at: http://www.v2.pjsir.org/index.php/biological-sciences/article/view/2274 (Accessed: 25 April 2026).