References
1. บทความจาก CNBC ชื่อ "Cities impose curfews, National Guard mobilizes as U.S. faces another night of unrest after George Floyd killing"
2. บทความจาก The Guardian ชื่อ "George Floyd: protesters clash with Secret Service as unrest comes to the White House"
3. บทความจาก NBC ชื่อ "Police tear gas protesters gathered near White House after George Floyd's death"
4. บทความจาก The Standard "'I can't breathe' protests heat up as curfews imposed in several US cities"