Historical clue formulations

• Enigma — 2025-08-04
• Brain twister — 2025-04-20
• Judges 14:14 has the only one in the Bible — 2014-09-20
• It doesn't have an obvious answer — 2009-02-07
• Mind teaser — 2001-06-12
• Turandot's test — 2001-03-11
• Mind twister — 2000-12-11
• Enigma — 2000-04-30
• Sphinx's offering — 1997-11-05
• Brain stumper — 1996-03-30