APA (7th ed.) Citation

Heimburg, W., & Davis, J. W. (2010). Gertrude's Marriage. Project Gutenberg.

Chicago Style (17th ed.) Citation

Heimburg, W., and J. W. Davis. Gertrude's Marriage. Project Gutenberg, 2010.

MLA (9th ed.) Citation

Heimburg, W., and J. W. Davis. Gertrude's Marriage. Project Gutenberg, 2010.

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