@article{LonnemannLinkersdoerferHasselhornetal.2013,
  author    = {Jan Lonnemann and Janosch Linkersd{\"o}rfer and Marcus Hasselhorn and Sven Lindberg},
  title     = {Developmental changes in the association between approximate number representations and addition skills in elementary school children},
  journal   = {Frontiers in psychology},
  volume    = {4},
  number    = {783},
  doi       = {10.3389/fpsyg.2013.00783},
  year      = {2013},
}