Cita APA

Walford, A. J., & Walford, A. J. (1966). Guide to reference materials (2. edition.). London: Library Association.

Citación estilo Chicago

Walford, Albert John, y Albert John Walford. Guide to Reference Materials. 2. edition. London: Library Association, 1966.

Cita MLA

Walford, Albert John, y Albert John Walford. Guide to Reference Materials. 2. edition. London: Library Association, 1966.