NFL: Kansas City Chiefs safety Husain Abdullah retires after concussion concerns
Bills' A. J. Tarpley cites concussions as reason to retire
Chiefs safety Abdullah retiring, citing health concerns
Bills sign free-agent centre Fernando Velasco
NFL says Husain Abdullah of Kansas City Chiefs shouldn't have been penalized for praying in celebration - ESPN
Buffalo Bills' A.J. Tarpley retiring over concussion concerns
What it would mean for the NFL to be able to diagnose CTE in the living
Husain Abdullah retires due to concussion concerns
Regular Season Game 7 - Chiefs vs. Bengals (10-21-18) by Kansas City Chiefs - Issuu
PDF) I Dont Think Its Worth the Risk: Media Framing of the Chris Borland Retirement in Digital and Print Media
22 NFL players who retired early, from Gronk to Barry Sanders
NFL faces new concussion-related lawsuit
CTE study offers more insight as Iowans struggle to make football safer