@phdthesis{Etzold2021,
  author      = {Heiko Etzold},
  title       = {Neue Zug{\"a}nge zum Winkelbegriff},
  type        = {doctoralthesis},
  pages       = {300},
  school      = {Universit{\"a}t Potsdam},
  doi       = {10.25932/publishup-50418},
  year        = {2021},
}