APA (7th ed.) Citation

Gies, F., & Gies, J. (1995). Cathedral, forge, and waterwheel: Technology and invention in the Middle Ages. Harperperennial.

Chicago Style (17th ed.) Citation

Gies, Frances, and Joseph Gies. Cathedral, Forge, and Waterwheel: Technology and Invention in the Middle Ages. New York: Harperperennial, 1995.

MLA (9th ed.) Citation

Gies, Frances, and Joseph Gies. Cathedral, Forge, and Waterwheel: Technology and Invention in the Middle Ages. Harperperennial, 1995.

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