Detroit Lions Star Wide Receiver Calvin Johnson Unexpectedly Retires
Calvin Johnson: Lions told him to change concussion story
Lions' Calvin Johnson through the years
Lions' Calvin Johnson through the years
Calvin Johnson opens up about his retirement
Calvin Johnson - Wikipedia
Lions offseason to-do list, starting with getting Calvin Johnson's answer
NFL notes: Once again, Lions lose a star in his prime - The Boston Globe
Calvin Johnson content, but didn't like treatment from Lions