Historical clue formulations

• Alien autopsies, crop circles and the like — 2017-10-01
• "The Hitler Diaries" and others — 2012-10-30
• E-mails from Nigerian princes, e.g. — 2009-06-24
• Some urban legends — 2005-02-25
• Big tricks — 2003-11-13
• Piltdown Man and others — 1995-06-12