Citazione APA

Walford, A. J. (1970). Guide to reference material (2nd ed.). The Library Association.

Stile di citazione Chicago

Walford, A J. Guide to Reference Material. 2nd ed. London: The Library Association, 1970.

Citazione MLA

Walford, A J. Guide to Reference Material. 2nd ed. The Library Association, 1970.