APA (7th ed.) Citation

Ashdown, C. H. (2012). British Castles. Project Gutenberg.

Chicago Style (17th ed.) Citation

Ashdown, Charles H. British Castles. Project Gutenberg, 2012.

MLA (9th ed.) Citation

Ashdown, Charles H. British Castles. Project Gutenberg, 2012.

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