APA (7th ed.) Citation

Upton, G. P. (2005). The Standard Operas (12th edition) Their Plots, Their Music, and Their Composers. Project Gutenberg.

Chicago Style (17th ed.) Citation

Upton, George P. The Standard Operas (12th Edition) Their Plots, Their Music, and Their Composers. Project Gutenberg, 2005.

MLA (9th ed.) Citation

Upton, George P. The Standard Operas (12th Edition) Their Plots, Their Music, and Their Composers. Project Gutenberg, 2005.

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