APA (7th ed.) Citation

Horton, C. M. (2008). Opportunities in Engineering. Project Gutenberg.

Chicago Style (17th ed.) Citation

Horton, Charles M. Opportunities in Engineering. Project Gutenberg, 2008.

MLA (9th ed.) Citation

Horton, Charles M. Opportunities in Engineering. Project Gutenberg, 2008.

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