APA (7th ed.) Citation

Erckmann-Chatrian. (2011). The Mysterious Sketch. Project Gutenberg.

Chicago Style (17th ed.) Citation

Erckmann-Chatrian. The Mysterious Sketch. Project Gutenberg, 2011.

MLA (9th ed.) Citation

Erckmann-Chatrian. The Mysterious Sketch. Project Gutenberg, 2011.

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