Cita APA (7a ed.)

Christie, A. (1984). The secret of chimneys (3a ed.). [s.n.].

Cita Chicago Style (17a ed.)

Christie, Agatha. The Secret of Chimneys. 3a ed. New York: [s.n.], 1984.

Cita MLA (9a ed.)

Christie, Agatha. The Secret of Chimneys. 3a ed. [s.n.], 1984.