@article{HammersteinKoenigDreisoerneretal.2021,
  author    = {Svenja Hammerstein and Christoph K{\"o}nig and Thomas Dreis{\"o}rner and Andreas Frey},
  title     = {Effects of COVID-19-related school closures on student achievement - a systematic review},
  journal   = {Frontiers in psychology},
  volume    = {12},
  number    = {art. 746289},
  pages     = {1 -- 8},
  doi       = {10.3389/fpsyg.2021.746289},
  year      = {2021},
}