Historical clue formulations

• Pick up again — 2024-07-30
• Brush up on — 2019-11-12
• Brush up on — 2015-05-16
• Brush up on — 2008-03-30
• Brush up on — 2001-08-26
• Master anew — 2001-07-15
• Brush up on — 2000-11-03