APA (7th ed.) Citation

City of London (England). Corporation. (1991). The official guide to the Mansion House. Corporation of London.

Chicago Style (17th ed.) Citation

City of London (England). Corporation. The Official Guide to the Mansion House. London: Corporation of London, 1991.

MLA (9th ed.) Citation

City of London (England). Corporation. The Official Guide to the Mansion House. Corporation of London, 1991.

Warning: These citations may not always be 100% accurate.