Liljedahl, P., Santos-Trigo, M., Malaspina, U., & Bruder, R. (2016). Problem Solving in Mathematics Education. Springer International Publishing : Imprint: Springer. https://doi.org/10.1007/978-3-319-40730-2

Liljedahl, Peter, Manuel Santos-Trigo, Uldarico Malaspina, and Regina Bruder. Problem Solving in Mathematics Education. Cham: Springer International Publishing : Imprint: Springer, 2016. https://doi.org/10.1007/978-3-319-40730-2.

Liljedahl, Peter, et al. Problem Solving in Mathematics Education. Springer International Publishing : Imprint: Springer, 2016. https://doi.org/10.1007/978-3-319-40730-2.