NFL announces more steps to reduce head injuries
NFL introduces Guardian Caps across league to limit number of brain injuries in preseason
New NFL Helmets - NFL Testing Validates Benefit of Guardian Caps
NFL's use of Guardian padded helmet caps in camp draws support and skepticism - The Athletic
Guardian Cap used by football teams to protect against head injury – The Denver Post
What is a Guardian Cap? Meet the NFL's newest safety measure
Could Guardian Caps be used in games? - NBC Sports
Giants react to NFL's new 'Guardian Caps' at training camps - Big Blue View
Guardian Cap Use a Concern for Watt, Saleh Early in Training Camp - Sports Illustrated
Guardian Caps: NFL requires use of helmet cover at training camps to reduce head injuries