Q. How do I determine when a copyright expires?

It is often difficult to determine if the copyright has expired on a work. The options below can assist.

• Peter Hirdle at Cornell University developed a complex chart that covers all aspects of copyright expiration. The chart is licensed for public use through Creative Commons.

• Lolly Gasaway at the University of North Carolina at Chapel Hill created a more abbreviated version at www.unc.edu/~unclng/public-d.htm.

• The U.S. Copyright office has listed online copyright records from 1978 to the present and provides helpful research information at www.copyright.gov/records/. Records prior to 1978 can only be researched manually by the U.S. Copyright Office for an hourly fee.