Historical clue formulations

• Riboflavin, alternatively — 2020-01-03
• Vitamin also known as riboflavin — 2019-10-09
• Stealth bomber, familiarly — 2018-12-30
• Vitamin a.k.a. riboflavin — 2016-07-08
• Riboflavin, familiarly — 2014-12-05
• Kind of bomber — 2009-01-20