Journals, JBAS, B. E Yabefa, S. Z Koroye, and G. O Ufuoma. 2023. “Effect of Extra Water on the Compressive Strength of Periwinkle Shell Ash Based Geopolymer Mortar”. Rivers State Univeristy Journal of Biology & Applied Sciences 3 (1). http://jbasjournals.com/index.php/rsujbas/article/view/54.