Murray Gell-Mann, Nobel-winning physicist who developed quark idea, dies at 89(washingtonpost.com)

https://www.washingtonpost.com/local/obituaries/murray-gell-mann-nobel-winning-physicist-who-developed-quark-idea-dies-at-89/2019/05/25/8a3b3d16-7e87-11e9-8bb7-0fc796cf2ec0_story.html