APA (7th ed.) Citation

Conan Doyle, A., & Tull, P. (1986). The sign of four (Unabridged.). Recorded Books Inc..

Chicago Style (17th ed.) Citation

Conan Doyle, Arthur, and Patrick Tull. The Sign of Four. Unabridged. Prince Frederick: Recorded Books Inc., 1986.

MLA (8th ed.) Citation

Conan Doyle, Arthur, and Patrick Tull. The Sign of Four. Unabridged. Recorded Books Inc., 1986.

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