S. Aboho, B. Anhwange, and G. Ber, “Screening of Achatina achatina and Pila ovata for Trace Metals in Makurdi Metropolis”, Pak. J. Nutr., vol. 8, no. 8, pp. 1170–1171, Jul. 2009, doi: 10.3923/pjn.2009.1170.1171.