APA (7th ed.) Citation

Hartnack, J. (1971). Philosophical problems: A modern introduction. Humanities Press.

Chicago Style (17th ed.) Citation

Hartnack, Justus. Philosophical Problems: A Modern Introduction. [New York]: Humanities Press, 1971.

MLA (9th ed.) Citation

Hartnack, Justus. Philosophical Problems: A Modern Introduction. Humanities Press, 1971.

Warning: These citations may not always be 100% accurate.