Zulkardi, Prahmana, R. C. I. and Putri, R. I. I. (2025) “In memory of Jan de Lange and Kees Hoogland: Honoring their legacy and contributions to mathematics education in Indonesia”, Journal on Mathematics Education, 16(2), pp. 753–762. doi: 10.22342/jme.v16i2.pp753-762.