Cita APA (7a ed.)

Collins, A., & Doyle, A. C. (1992). The sign of four. Heinemann.

Cita Chicago Style (17a ed.)

Collins, Anne, y Arthur Conan Doyle. The Sign of Four. Oxford [etc.]: Heinemann, 1992.

Cita MLA (9a ed.)

Collins, Anne, y Arthur Conan Doyle. The Sign of Four. Heinemann, 1992.