Portugal, M. R. B., & Joaquin, N. B. (2014). Multiple model approach: Effects on student conceptual and procedural understanding of fraction. College of Education, University of the Philippines Diliman.

Portugal, Mary Rose B., and Nympha Beltran Joaquin. Multiple Model Approach: Effects on Student Conceptual and Procedural Understanding of Fraction. Quezon City: College of Education, University of the Philippines Diliman, 2014.

Portugal, Mary Rose B., and Nympha Beltran Joaquin. Multiple Model Approach: Effects on Student Conceptual and Procedural Understanding of Fraction. College of Education, University of the Philippines Diliman, 2014.