The NFL has long said that it did not try to cover up the effect of concussions and the long-term issues related to the injuries to players in the league, but a new book excerpt from 'League of Denial: The NFL, Concussions and the Battle for Truth' argues against that claim.

According to ESPN.com, Sports Illustrated and ESPN the Magazine published a small part of the book by reporters Mark Fainaru-Wada and Steve Fainaru, which details how the NFL used various methods to cover up and also to "discredit" scientists looking into the effect of football and concussions for years, while also hiding some of those figures from the public.

The book and the accompanying documentary got added focus after the NY Times reported that ESPN broke their partnership deal with PBS and the show Frontline after the NFL pressured the network to do so. That act echoes what is described in the book, which was put together with information and research found over the past year and so far NFL officials have not commented on the book.

Click here for the book excerpt.

Here are a couple quick excerpts, courtesy of eSPN.com and SI.com:

• Two original members of a concussion committee established by Tagliabue disavowed the committee's major findings, including the NFL's assertion that concussions were minor injuries that never led to long-term brain injury.

• Beginning in 2000, some of the country's top neuroscientists warned the NFL that football led to higher rates of depression, memory loss, dementia and brain damage.

• The league in 2005 tried unsuccessfully to have medical journals retract the published work of several independent concussion researchers.

• As far back as 1999, the NFL's retirement board paid more than $2 million in disability payments to former players after concluding football gave them brain damage. But it would be nearly a decade before league executives would publicly acknowledge a link.