APA (7th ed.) Citation

Higgins, J. (2001). The Keys of hell. Harper Collins Publishers.

Chicago Style (17th ed.) Citation

Higgins, Jack. The Keys of Hell. London: Harper Collins Publishers, 2001.

MLA (9th ed.) Citation

Higgins, Jack. The Keys of Hell. Harper Collins Publishers, 2001.

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