@article{MuellerHagenVanninietal.2021,
  author    = {Bettina M{\"u}ller and Alexa von Hagen and Natalie Vannini and Gerhard B{\"u}ttner},
  title     = {Measurement of the effects of school psychological services: a scoping review},
  journal   = {Frontiers in psychology},
  volume    = {12},
  number    = {art. 606228},
  pages     = {1 -- 15},
  doi       = {10.3389/fpsyg.2021.606228},
  year      = {2021},
}