APA (7th ed.) Citation

(1977). The New Encyclopaedia Britannica (15th ed.). Encyclopaedia Britannica.

Chicago Style (17th ed.) Citation

The New Encyclopaedia Britannica. 15th ed. Chicago [etc.]: Encyclopaedia Britannica, 1977.

MLA (9th ed.) Citation

The New Encyclopaedia Britannica. 15th ed. Encyclopaedia Britannica, 1977.

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