APA (7th ed.) Citation

Asimov, I. (2016). Foundation and empire (NA.). Harper Voyager.

Chicago Style (17th ed.) Citation

Asimov, Isaac. Foundation and Empire. NA. London: Harper Voyager, 2016.

MLA (9th ed.) Citation

Asimov, Isaac. Foundation and Empire. NA. Harper Voyager, 2016.

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