APA (7th ed.) Citation

Boelen, B. J. (1968). Existential thinking: A philosophical orientation. Duquesne University Press.

Chicago Style (17th ed.) Citation

Boelen, Bernard J. Existential Thinking: A Philosophical Orientation. [Pittsburgh]: Duquesne University Press, 1968.

MLA (9th ed.) Citation

Boelen, Bernard J. Existential Thinking: A Philosophical Orientation. Duquesne University Press, 1968.