APA (7th ed.) Citation

Oppenheim, E. P. (2011). Mysterious Mr. Sabin. Project Gutenberg.

Chicago Style (17th ed.) Citation

Oppenheim, E. Phillips. Mysterious Mr. Sabin. Project Gutenberg, 2011.

MLA (9th ed.) Citation

Oppenheim, E. Phillips. Mysterious Mr. Sabin. Project Gutenberg, 2011.

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