Hooligans, Ultras, Activists: Polish Football Fandom in Sociological Perspective | SpringerLink
World Football's 10 Most Dangerous Fan Bases | News, Scores, Highlights, Stats, and Rumors | Bleacher Report
The bloodthirsty new generation of hooligans dragging football back to the 1970s and bringing terror to the game – The Sun | The Sun
List of hooligan firms - Wikipedia
25 Fearsome Soccer Hooligan Gangs To Avoid
BRUISINGS, BURNINGS AND BEATINGS: Europe's Worst Soccer Hooligans
Photos: Europe's Soccer Hooligans - WSJ
Whitehall fears Russian football hooligans had Kremlin links | Football violence | The Guardian
European Football: The 10 Craziest Ultras Groups | Balkanski Navijaci
6 of the most dangerous hooligans in Italy - Riot With Style - The best page about hooligans and ultras!
Hooligans Abroad: Behaviour and Control of... by Williams, John
Why do a lot of hooligan related violence/fights happen in football matches in Eastern/Central Europe (like Russia, Poland, Serbia etc)? What do general fans think about these groups of football hooligans? -
Inside the dark world of Bulgaria's football hooligan firms – gouged out eyes, Nazi salutes and strict violence 'rules' – The Sun | The Sun
Football hooligans to launch 'European Defence League' in Amsterdam
Which country has the most powerful football hooligans nowadays? - Quora
British hooligan expert says Marseille 2016 the worst yet and French police tactics outdated
10 most dangerous ultras of world football
10 football clubs with the most violent fans
Ugly Violence – DW – 06/12/2016
10 Most Violent Ultra Groups In Football! - YouTube
Legalizing soccer hooliganism won't prevent fan violence, say experts | CBC Radio
This is how the Russian authorities plan on preventing hooliganism at the 2018 World Cup | The Independent | The Independent
