APA (7th ed.) Citation

British Museum, Walker, S., & Ashton, S. (2003). Cleopatra reassessed. British Museum.

Chicago Style (17th ed.) Citation

British Museum, Susan Walker, and Sally-Ann Ashton. Cleopatra Reassessed. London: British Museum, 2003.

MLA (9th ed.) Citation

British Museum, et al. Cleopatra Reassessed. British Museum, 2003.