APA (7th ed.) Citation

(2011). Encyclopaedia Britannica, 11th Edition, Volume 12, Slice 6 "Groups, Theory of" to "Gwyniad". Project Gutenberg.

Chicago Style (17th ed.) Citation

Encyclopaedia Britannica, 11th Edition, Volume 12, Slice 6 "Groups, Theory of" to "Gwyniad". Project Gutenberg, 2011.

MLA (9th ed.) Citation

Encyclopaedia Britannica, 11th Edition, Volume 12, Slice 6 "Groups, Theory of" to "Gwyniad". Project Gutenberg, 2011.

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