APA (7th ed.) Citation

Wagnalls, M. (2011). Stars of the Opera. Project Gutenberg.

Chicago Style (17th ed.) Citation

Wagnalls, Mabel. Stars of the Opera. Project Gutenberg, 2011.

MLA (9th ed.) Citation

Wagnalls, Mabel. Stars of the Opera. Project Gutenberg, 2011.

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