Hartwell, D. Dogs against darkness: The story of the Seeing Eye. Rich & Cowan.
Cita Chicago (17th ed.)Hartwell, Dickson. Dogs Against Darkness: The Story of the Seeing Eye. London: Rich & Cowan.
Cita MLA (8th ed.)Hartwell, Dickson. Dogs Against Darkness: The Story of the Seeing Eye. Rich & Cowan.
Atenció: Aquestes cites poden no estar 100% correctes.