ABRENICA, Mary Grace; ALBA, Jane; DUMAGO, Patricia Mae; EVANGELISTA, Mark; MONREAL, Jenalyn; SECIBAN, Kisha Ann. Development, Evaluation and Heavy Metal Analysis of Tailor’s Chalk Using Eggshell and Green Apple Snail Shell in Three Formulations. International Journal of Education, Research, and Innovation Perspectives, Philippines, v. 2, n. 5, p. 1125–1134, 2026. DOI: 10.5281/zenodo.20324229. Disponível em: https://ijerip.erio.org.ph/index.php/articles/article/view/705. Acesso em: 22 may. 2026.