APA (7th ed.) Citation

Houston, E. J. (2013). The Wonder Book of Volcanoes and Earthquakes. Project Gutenberg.

Chicago Style (17th ed.) Citation

Houston, Edwin J. The Wonder Book of Volcanoes and Earthquakes. Project Gutenberg, 2013.

MLA (9th ed.) Citation

Houston, Edwin J. The Wonder Book of Volcanoes and Earthquakes. Project Gutenberg, 2013.

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