Calvin Johnson on concussions, injuries - Sports Illustrated
Calvin Johnson -- Detroit Lions need to win a Super Bowl - ESPN
Report: Calvin Johnson told Caldwell he's retiring
Detroit Lions land 5 players on ESPN's all-decade team for NFC North
Calvin Johnson - Wikipedia
Jaguars reportedly interested in trading for Calvin Johnson - Big Cat Country
Calvin Johnson retirement: Detroit Lions WR to end career - Sports Illustrated
Dallas Cowboys: Imagine Calvin Johnson wearing the Star
Calvin Johnson: Concussions played role in retirement
Former Detroit Lions All-Pro Calvin Johnson happy in retirement - ESPN - NFL Nation- ESPN
Calvin Johnson retires: 'I have played my last game of football' - ABC7 Chicago