@inproceedings{pme336559-greefrathdevelopmentan,
  title={DEVELOPMENT AND VALIDATION OF A TEST INSTRUMENT FOR ASSESSING FUNCTIONAL THINKING IN SECONDARY EDUCATION},
  author={Greefrath, Gilbert and Bommert, Emilia and Kirsten, Katharina},
  booktitle={Proceedings of the International Group for the Psychology of Mathematics Education, Volume 1},
  year={2026},
  pages={531--538},
  publisher={Psychology of Mathematics Education (PME)},
  issn={2790-3648}
}