APA (7th ed.) Citation

Clark, J. (2010). Penny Nichols and the Knob Hill Mystery. Project Gutenberg.

Chicago Style (17th ed.) Citation

Clark, Joan. Penny Nichols and the Knob Hill Mystery. Project Gutenberg, 2010.

MLA (9th ed.) Citation

Clark, Joan. Penny Nichols and the Knob Hill Mystery. Project Gutenberg, 2010.

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