Frick. Paul in the Grip of the Philosophers. Augsburg Fortress Publishers.
Citazione stile Chigago Style (17a edizione)Frick. Paul in the Grip of the Philosophers. Augsburg Fortress Publishers.
Citatione MLA (8a ed.)Frick. Paul in the Grip of the Philosophers. Augsburg Fortress Publishers.
Attenzione: Queste citazioni potrebbero non essere precise al 100%.