Cita APA (7th ed.)

Butler, G. (1969). Coffin's dark number. Bles.

Cita Chicago (17th ed.)

Butler, Gwendoline. Coffin's Dark Number. London: Bles, 1969.

Cita MLA (8th ed.)

Butler, Gwendoline. Coffin's Dark Number. Bles, 1969.