APA (7th ed.) Citation

Machen, J. G. (2013). The Origin of Paul's Religion. Project Gutenberg.

Chicago Style (17th ed.) Citation

Machen, J. Gresham. The Origin of Paul's Religion. Project Gutenberg, 2013.

MLA (9th ed.) Citation

Machen, J. Gresham. The Origin of Paul's Religion. Project Gutenberg, 2013.

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