APA (7th ed.) Citation

Powell, K., & Smith, G. (2006). 30 St Mary Axe: A tower for London. Merrell Pub..

Chicago Style (17th ed.) Citation

Powell, Kenneth, and Grant Smith. 30 St Mary Axe: A Tower for London. London ; New York: Merrell Pub., 2006.

MLA (9th ed.) Citation

Powell, Kenneth, and Grant Smith. 30 St Mary Axe: A Tower for London. Merrell Pub., 2006.

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