APA (7th ed.) Citation

(2013). Opium Eating An Autobiographical Sketch. Project Gutenberg.

Chicago Style (17th ed.) Citation

Opium Eating An Autobiographical Sketch. Project Gutenberg, 2013.

MLA (9th ed.) Citation

Opium Eating An Autobiographical Sketch. Project Gutenberg, 2013.

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