Former Patriots TE Rob Gronkowski confirms that he will remain retired - A to Z Sports
Four-time Super Bowl champion Rob Gronkowski retires from NFL for second time, NFL
Rob Gronkowski on retiring from NFL at age 29: 'I didn't even want to negotiate' - ABC News
Rob Gronkowski retirement: Patriots TE unhappy in 2017 - Sports Illustrated
Rob Gronkowski retires: New England Patriots tight end steps away from NFL – The Denver Post
New England Patriots tight end Rob Gronkowski retires from the NFL
Patriots tight end Rob Gronkowski announces retirement on Instagram
Rob Gronkowski retires from the NFL again - The Boston Globe
Rob Gronkowski: Only this ex-Patriots coach could lure me out of retirement – NBC Sports Boston
Former Patriots TE says which NFL coach could bring him out of retirement
Tampa Bay Buccaneers TE Rob Gronkowski to retire, NFL News, Rankings and Statistics
Rob Gronkowski: Second Unretirement Will Not Happen