APA (7th ed.) Citation

Tolkien, J. R. R., & Tolkien, C. (2006). Unfinished tales of Númenor and Middle-earth. HarperCollins.

Chicago Style (17th ed.) Citation

Tolkien, J. R. R., and Christopher Tolkien. Unfinished Tales of Númenor and Middle-earth. London: HarperCollins, 2006.

MLA (9th ed.) Citation

Tolkien, J. R. R., and Christopher Tolkien. Unfinished Tales of Númenor and Middle-earth. HarperCollins, 2006.

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