Calkins, M. W. (1919). The persistent problems of philosophy: An introduction to metaphysics through the study of modern systems (4th ed., rev.). Macmillan.
Citazione stile Chigago Style (17a edizione)Calkins, Mary Whiton. The Persistent Problems of Philosophy: An Introduction to Metaphysics Through the Study of Modern Systems. 4th ed., rev. New York: Macmillan, 1919.
Citatione MLA (9a ed.)Calkins, Mary Whiton. The Persistent Problems of Philosophy: An Introduction to Metaphysics Through the Study of Modern Systems. 4th ed., rev. Macmillan, 1919.
Attenzione: Queste citazioni potrebbero non essere precise al 100%.
