APA (7th ed.) Citation

Kurzweil, R. (1999). The age of spiritual machines: When computers exceed human intelligence. Viking.

Chicago Style (17th ed.) Citation

Kurzweil, Ray. The Age of Spiritual Machines: When Computers Exceed Human Intelligence. New York: Viking, 1999.

MLA (9th ed.) Citation

Kurzweil, Ray. The Age of Spiritual Machines: When Computers Exceed Human Intelligence. Viking, 1999.