CUTAMORA, Manuel. Predictive Influence of Teacher Challenges and School Head Support on Teaching Effectiveness in Multigrade Classrooms in Lingig I District, Division of Surigao Del Sur: A Descriptive-Correlational Study. International Journal of Education, Research, and Innovation Perspectives, Philippines, v. 2, n. 2, p. 30–60, 2026. DOI: 10.5281/zenodo.18475572. Disponível em: https://ijerip.erio.org.ph/index.php/articles/article/view/34. Acesso em: 22 mar. 2026.