Otobo, G., Endurance Fegor Isoje and Augustina Ufuoma Igbuku (2023) “Hazardous Nature of Native Chalk (Calabash chalk)”, International Journal of Sciences: Basic and Applied Research (IJSBAR), 71(1), pp. 31–36. Available at: https://www.gssrr.org/JournalOfBasicAndApplied/article/view/16177 (Accessed: 1 May 2026).