APA (7th ed.) Citation

Olsen, R. G. (1962). An introduction to existentialism / by R.G. Olsen. Dover Pubs.

Chicago Style (17th ed.) Citation

Olsen, R. G. An Introduction to Existentialism / by R.G. Olsen. Dover Pubs, 1962.

MLA (9th ed.) Citation

Olsen, R. G. An Introduction to Existentialism / by R.G. Olsen. Dover Pubs, 1962.

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