Former Patriots TE Rob Gronkowski announces retirement for 2nd time
Rob Gronkowski retires from the NFL again - The Boston Globe
Tom Brady: Rob Gronkowski 'shocked' by former team-mate's retirement aged 45, saying he could still play until he is 50, NFL News
Rob Gronkowski retires from NFL after 11 seasons, 4 Super Bowls
Rob Gronkowski retires: New England Patriots tight end steps away from NFL – The Denver Post
Tight end Rob Gronkowski announces his retirement from NFL after 11 seasons spent with both the New England Patriots and Tampa Bay Buccaneers
Rob Gronkowski's Money, Endorsements, and How He Spends It
Rob Gronkowski: Tampa Bay Buccaneers tight end in photos
Rob Gronkowski retirement: How the future HOF tight end's decision to hang up his cleats affects the Buccaneers