Citazione APA

Doyle, A. C. (1994). The Sign of the Four (1st.). OUP.

Stile di citazione Chicago

Doyle, Arthur Conan. The Sign of the Four. 1st. New York: OUP, 1994.

Citazione MLA

Doyle, Arthur Conan. The Sign of the Four. 1st. OUP, 1994.