Wired: Inside the Cyberattack That Shocked the US Government, October 2016

Wikipedia: EINSTEIN (US_CERT Program)

ThreatConnect: The Anthem Hack: All Roads Lead to China

House Oversight Committee Democratic response to Committee report, October 2016

CNN: FBI Arrests Chinese National in OPM Data Breach, August 24 2017

CSO Online -- The OPM hack explained: Bad security practices meet China's Captain America, November 8, 2018

Washington Post: Chinese government has arrested hackers it says breached OPM database, December 2, 2015

Network Security News: OPM Data Breach Apr 20, 2017 • Cyril Saade, Benjamin Li, Seunghun Oh

FedSmith: Bolton Confirms China Behind OPM Data Breaches, Sept 21, 2018