APA (7th ed.) Citation

(2006). Encyclopaedia Britannica, 11th Edition, Volume 4, Part 4 "Bulgaria" to "Calgary". Project Gutenberg.

Chicago Style (17th ed.) Citation

Encyclopaedia Britannica, 11th Edition, Volume 4, Part 4 "Bulgaria" to "Calgary". Project Gutenberg, 2006.

MLA (9th ed.) Citation

Encyclopaedia Britannica, 11th Edition, Volume 4, Part 4 "Bulgaria" to "Calgary". Project Gutenberg, 2006.

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