Historical clue formulations

• Circle measure: Abbr. — 2013-07-29
• Geometry meas. — 2012-07-28
• Circle meas. — 2011-04-19
• Geom. measure — 2009-12-20
• Circular meas. — 2009-09-30
• Geom. line — 2006-10-29
• Circle meas. — 2002-03-17
• Cir. bisector — 1995-07-05