Historical clue formulations

• Convincing, as an argument — 2014-02-20
• Well-thought-out — 2010-02-02
• Convincing, as an argument — 2008-03-12
• Telling — 2006-04-07
• Convincing — 2002-02-03
• Like a good argument — 2001-09-23
• Forceful — 2001-03-24
• Sound — 1999-03-03
• Penetrating — 1997-02-22