Historical clue formulations

• Chin stroker's comment — 2018-03-07
• "Thinking ..." — 2016-10-23
• "So many choices ..." — 2016-09-29
• "Hmm ..." — 2015-10-06
• "Hmmm ..." — 2013-09-16
• "I'll try to think of something ..." — 2008-08-18
• "Hmmm ..." — 2007-03-12
• "Hmmm …" — 2006-10-04
• Ponderer's phrase — 1996-10-13