NECOR, Dexter. Exploring Students’ Level of Conceptual Understanding on Periodicity. JPAIR Multidisciplinary Research, Philippines, v. 33, n. 1, p. 136–154, 2018. DOI: 10.7719/jpair.v33i1.609. Disponível em: https://www.philair.ph/index.php/jpair/article/view/609. Acesso em: 2 may. 2025.