Historical clue formulations

• Jean Arp, e.g. — 2026-03-19
• Like some Marcel Duchamp works — 2022-06-17
• Marcel Duchamp, e.g. — 2020-05-31
• Arp or Duchamp — 2013-12-01
• 67-Down, for one — 1996-12-22
• Arp was one — 1996-08-30
• Marcel Duchamp, e.g. — 1995-11-26