APA (7th ed.) Citation

Powell, M. A. (1999). The Sumerian Agriculture Group: A Brief History.

Chicago Style (17th ed.) Citation

Powell, Marvin A. The Sumerian Agriculture Group: A Brief History. 1999.

MLA (8th ed.) Citation

Powell, Marvin A. The Sumerian Agriculture Group: A Brief History. 1999.

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