APA (7th ed.) Citation

National Gallery (Great Britain) & Holmes, C. J. (1931). National Gallery Trafalgar Square: Illustrated guide (6th and rev. ed.). The Gallery.

Chicago Style (17th ed.) Citation

National Gallery (Great Britain) and C. J. Holmes. National Gallery Trafalgar Square: Illustrated Guide. 6th and rev. ed. London: The Gallery, 1931.

MLA (8th ed.) Citation

National Gallery (Great Britain) and C. J. Holmes. National Gallery Trafalgar Square: Illustrated Guide. 6th and rev. ed. The Gallery, 1931.

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