Historical clue formulations

• Mystery writer Marsh — 2019-03-03
• Mystery writer Marsh — 2018-01-05
• Mystery writer Marsh — 2017-03-14
• Marsh of mystery — 2016-01-24
• Marsh of detective fiction — 2013-04-07
• Mystery writer Marsh — 2011-07-20
• Marsh of mysteries — 2010-07-25
• Contemporary of Agatha and Erle — 2008-04-04
• Marsh of mystery — 2005-04-08
• Marsh of mystery — 2004-01-23
• Marsh of mystery — 2003-06-24
• Author Marsh — 2002-08-04
• Mystery writer Marsh — 2000-10-29
• Writer Marsh — 1997-11-29
• Author Marsh — 1997-08-24
• Marsh of mystery — 1997-07-04
• Writer Marsh — 1995-04-04
• First name in mysteries — 1994-11-04