APA (7th ed.) Citation

Conan Doyle, A. (1992). The sign of four. Heinemann Elt.

Chicago Style (17th ed.) Citation

Conan Doyle, Arthur. The Sign of Four. Oxford, Inglaterra: Heinemann Elt, 1992.

MLA (9th ed.) Citation

Conan Doyle, Arthur. The Sign of Four. Heinemann Elt, 1992.

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