@article{GuensterWeigand2020,
  author    = {Stephan Michael G{\"u}nster and Hans-Georg Weigand},
  title     = {Designing digital technology tasks for the development of functional thinking},
  journal   = {ZDM - Mathematics Education},
  volume    = {52},
  doi       = {10.1007/s11858-020-01179-1},
  year      = {2020},
}