Last seen in:
- Universal - Jun 17 2020
- Universal - Feb 15 2020
- The Washington Post Sunday - Oct 29 2017
- Wall Street Journal - Aug 11 2014 - Puzzle 150
- Universal - Nov 3 2011
- The Chronicle of Higher Education - Jan 21 2011
- Universal - May 9 2006
- Wall Street Journal - Sep 2 2005 - September 2, 2005 - Modern-Day Herculean Labors