APA (7th ed.) Citation

Brill, E. C., & Wolf, W. H. (2013). The Secret Cache An Adventure and Mystery Story for Boys. Project Gutenberg.

Chicago Style (17th ed.) Citation

Brill, E. C., and W. H. Wolf. The Secret Cache An Adventure and Mystery Story for Boys. Project Gutenberg, 2013.

MLA (9th ed.) Citation

Brill, E. C., and W. H. Wolf. The Secret Cache An Adventure and Mystery Story for Boys. Project Gutenberg, 2013.

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