Marbán, J.M. and Sintema, E.J. 2020. Pre-service secondary teachers’ knowledge of the function concept: A cluster analysis approach. JRAMathEdu (Journal of Research and Advances in Mathematics Education). 5, 1 (Feb. 2020), 38–53. DOI:https://doi.org/10.23917/jramathedu.v5i1.9703.