Historical clue formulations

• At bottom — 2021-07-24
• Underneath all the layers — 2015-12-26
• At bottom — 2015-11-13
• Fundamentally — 2015-05-06
• Basically — 2012-12-23
• Fundamentally — 2004-01-13
• Basically — 2002-12-01
• Basically — 1999-05-29
• Basically — 1996-04-06
• Basically — 1996-02-23