APA (7th ed.) Citation

Harte, B., & Keller, A. I. (2010). Her Letter His Answer and Her Last Letter. Project Gutenberg.

Chicago Style (17th ed.) Citation

Harte, Bret, and Arthur Ignatius Keller. Her Letter His Answer and Her Last Letter. Project Gutenberg, 2010.

MLA (9th ed.) Citation

Harte, Bret, and Arthur Ignatius Keller. Her Letter His Answer and Her Last Letter. Project Gutenberg, 2010.

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