Packers Share Thoughts on Wearing Guardian Caps at Camp, WTAQ News Talk, 97.5 FM · 1360 AM
Packers LB De'Vondre Campbell on wearing Guardian Caps: 'I just think it's stupid'
NFL Network: Guardian Caps in use at training camps
Guardian Caps: Why some NFL players are wearing them in training camps
What are Guardian Caps and how are they helping football teams?
Guardian Caps - Are the soft-shelled football helmet covers effective at limiting head injuries? - ESPN
NFL players wear Guardian Caps to reduce head trauma during training camp
Arizona Cardinals' J.J. Watt critical of Guardian Cap: 'Feel like a bobblehead' - ESPN
Guardian Caps: Why some NFL players are wearing them in training camps