Gilde, W. (1972). Erfinden, was noch niemals war. Urania Verlag.
Citazione stile Chigago Style (17a edizione)Gilde, Werner. Erfinden, Was Noch Niemals War. Leipzig: Urania Verlag, 1972.
Citatione MLA (8a ed.)Gilde, Werner. Erfinden, Was Noch Niemals War. Urania Verlag, 1972.
Attenzione: Queste citazioni potrebbero non essere precise al 100%.