@article{LonnemannHasselhorn2018,
  author    = {Jan Lonnemann and Marcus Hasselhorn},
  title     = {Fr{\"u}he mathematische Bildung},
  journal   = {Fr{\"u}he Bildung},
  series    = {Aktuelle Forschungstrends und Perspektiven},
  volume    = {7},
  number    = {3},
  pages     = {129 -- 134},
  doi       = {10.1026/2191-9186/a000379},
  year      = {2018},
}