APA (7th ed.) Citation

Piper, H. B. (2006). The Answer. Project Gutenberg.

Chicago Style (17th ed.) Citation

Piper, H. Beam. The Answer. Project Gutenberg, 2006.

MLA (9th ed.) Citation

Piper, H. Beam. The Answer. Project Gutenberg, 2006.

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