APA (7th ed.) Citation

(1993). The New Book Of Knowledge: Volume 21-Index. Grolier Incorporated.

Chicago Style (17th ed.) Citation

The New Book Of Knowledge: Volume 21-Index. USA: Grolier Incorporated, 1993.

MLA (9th ed.) Citation

The New Book Of Knowledge: Volume 21-Index. Grolier Incorporated, 1993.

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