APA (7th ed.) Citation

Carroll, L. (2011). Eight or Nine Wise Words about Letter-Writing. Project Gutenberg.

Chicago Style (17th ed.) Citation

Carroll, Lewis. Eight or Nine Wise Words About Letter-Writing. Project Gutenberg, 2011.

MLA (9th ed.) Citation

Carroll, Lewis. Eight or Nine Wise Words About Letter-Writing. Project Gutenberg, 2011.

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