Explainer: What happened to Damar Hamlin?
Physicians explain incredibly rare event that 'likely caused' Damar Hamlin's cardiac arrest
Damar Hamlin, NFL Player in Critical Condition, is Defying Odds
Damar Hamlin may have suffered freak 'one-in-200 million' injury that shuts off blood to brain
Bills' remarkably improved Damar Hamlin asks: 'Did we win?' - Los Angeles Times
What is commotio cordis, which NFL player Damar Hamlin says stopped his heart?
Buffalo Bills star Damar Hamlin's on-field collapse puts spotlight on cardiac arrest in young people - Good Morning America
What happened to Damar Hamlin? Explaining Commotio Cordis
Bills' Hamlin in critical condition after collapse on field - The San Diego Union-Tribune
Bills' Damar Hamlin may have suffered heart arrhythmia, experts say - The Washington Post
NFL star Damar Hamlin is awake and holding family members' hands, three days after collapsing on field - ABC News
Damar Hamlin, cardiac arrest and what it takes to boost the odds of survival : NPR
What Is Cardiac Arrest? What to Know About Why Damar Hamlin Collapsed - WSJ