Sports-related concussions not proved to cause later brain disease, says expert group, Science

Abnormal Levels of a Protein Linked to C.T.E. Found in N.F.L Players' Brains, Study Shows - The New York Times

Concussions and Traumatic Brain Injuries in Football: What We Know We Don't Know

Multiple Concussions: Long-Term Effects and Treatment Options

Sports-related concussions tied to brain disease

NFL Board Paid $2M to Players While League Denied Football-Concussion Link

The Forgotten History of Head Injuries in Sports

Scientists discover concussion biomarker - Northwestern Now

Concussions: Are High School Sports Worth the Risk?

Concussion in 20s could increase the risk of dementia by 60 per cent, Lancet study finds

Concussions: Can cap keep football players' heads in game? – Orange County Register

Ninety-nine percent of ailing NFL player brains show hallmarks of neurodegenerative disease, autopsy study finds, Science