Cita APA (7a ed.)

(1987). Walford's guide to reference material (4th ed.). Library Association.

Cita Chicago Style (17a ed.)

Walford's Guide to Reference Material. 4th ed. London: Library Association, 1987.

Cita MLA (9a ed.)

Walford's Guide to Reference Material. 4th ed. Library Association, 1987.