APA (7th ed.) Citation

Prichard, K. S. (2011). The Black Opal. Project Gutenberg.

Chicago Style (17th ed.) Citation

Prichard, Katharine Susannah. The Black Opal. Project Gutenberg, 2011.

MLA (9th ed.) Citation

Prichard, Katharine Susannah. The Black Opal. Project Gutenberg, 2011.

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