Historical clue formulations

• Winter bugs — 2023-07-10
• Winter bugs — 2021-08-18
• Winter ailments — 2016-10-17
• Winter bugs — 2013-07-03
• Seasonal threats — 2012-07-31
• Some shot targets — 2011-12-15
• Fever causes — 2008-06-08
• Unwelcome strains — 2003-09-25
• Bugs — 1998-05-31
• Strains in the winter? — 1998-02-15
• Nasty bugs — 1997-10-30