Cardiac arrest is often fatal, but doctors say certain steps can boost survival odds
How an NFL hit like Damar Hamlin's can stop a heart - Gothamist
Buffalo Bills' Damar Hamlin critical after collapse on field - WHYY
Shows of support and signs of unease mark the first NFL Sunday since Hamlin's injury
Buffalo Bills safety Damar Hamlin exits game via ambulance after scary collapse, requires CPR - On3
Monday Night Football Game postponed by NFL after collapse of Bills' Safety
Buffalo Bills player is in critical condition after collapsing in game : NPR
Damar Hamlin suffered cardiac arrest during game, heartbeat restored on field, Bills say
Buffalo safety and former Pitt star Damar Hamlin in critical condition after collapse on field