These guidelines have been endorsed by the following organizations: the NFL players association, (NFLPA) National Association of Athletic Trainers, (NATA) the American Football Coaches Association, the Neurocritical Care Society, the Child Neurology Society, the National Association of Emergency Medical Service Physicians, the National Association of School Psychologists, as well as the Child Neurology Society.

FORBES: Safety Prevails -- In Updated Guidelines To Manage Concussions

The guidelines are endorsed by the American Football Coaches Association, the National Association of Emergency Medical Service Physicians and the National Football League Players Association.

WSJ: Tougher Rules Advised for Athletes After Concussion

The accusations were presented by Chuck Blazer, American citizen and head of the Confederation Of North, Central American And Caribbean Association Football (CONCACAF).

FORBES: FIFA Chief Sepp Blatter To Face Ethics Committee Over Bribe Scandal

Two studies published in the Journal of the American Medical Association - on football in the UK and the US - have found a link between multiple concussions and neuropsychological problems.

BBC: 'Brain damage risk' from popular sports

The United States Football League, the World Football League, the World Hockey Association, and the American Basketball Association all lasted far longer than the XFL, despite the fact that none had network television contracts in their first seasons.

FORBES: Top Of The News: XFL Exterminated

Certainly, this is a positive story at a time when some other American sports are flailing (the National Basketball Association is on strike, college football is mired in a paedophile scandal).

ECONOMIST: Major League Soccer��s big investment seems to have paid off