APA (7th ed.) Citation

South, R. (2013). The Butterflies of the British Isles. Project Gutenberg.

Chicago Style (17th ed.) Citation

South, Richard. The Butterflies of the British Isles. Project Gutenberg, 2013.

MLA (9th ed.) Citation

South, Richard. The Butterflies of the British Isles. Project Gutenberg, 2013.

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