Historical clue formulations

• "___ thousand times ..." — 2017-09-08
• "... ___ thousand times ..." — 2009-06-09
• When doubled, a book by Gauguin — 2008-07-04
• "___ thousand times ..." — 2001-03-30
• "...___ thousand times..." — 2000-08-06
• "___thousand times..." — 1996-01-13
• When doubled, a Gauguin book — 1994-10-28