APA (7th ed.) Citation

Hungerford, E. (2012). The Railroad Problem. Project Gutenberg.

Chicago Style (17th ed.) Citation

Hungerford, Edward. The Railroad Problem. Project Gutenberg, 2012.

MLA (9th ed.) Citation

Hungerford, Edward. The Railroad Problem. Project Gutenberg, 2012.

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