APA (7th ed.) Citation

The new encyclopaedia Britannica (15. ed., [18. print.].). Encyclopaedia Britannica.

Chicago Style (17th ed.) Citation

The New Encyclopaedia Britannica. 15. ed., [18. print.]. Chicago: Encyclopaedia Britannica.

MLA (9th ed.) Citation

The New Encyclopaedia Britannica. 15. ed., [18. print.]. Encyclopaedia Britannica.

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