“Analysis and Purification of Nkalagu (Nigeria) Limestone and Poultry Eggshells for the Production of Paint Grade Calcium Carbonate: Short Communication”, Pakistan Journal of Scientific & Industrial Research, vol. 48, no. 6, pp. 433–435, Dec. 2005, Accessed: Mar. 10, 2026. [Online]. Available: https://www.v2.pjsir.org/index.php/biological-sciences/article/view/1440