Historical clue formulations

• ___-poly — 2007-07-22
• ___-poly — 2001-07-17
• ___-poly — 2000-08-01
• ___-poly — 1997-06-03
• ___-poly — 1997-05-08
• ___-poly — 1996-07-28
• ___-poly — 1996-06-11