@phdthesis{Poltz2018,
  author      = {Nadine Poltz},
  title       = {Die Entwicklung numerisch-mathematischer Fertigkeiten im Vorschulalter},
  type        = {doctoralthesis},
  pages       = {269},
  school      = {Universit{\"a}t Potsdam},
  year        = {2018},
}