Research into Football Violence 
Site explaining academic study by Robin Manser into 'hooliganism' and the policing of English fans abroad.
http://hooligansfootball.homestead.com/Football Unites, Racism Divides 
A study of race and football.
http://www.furd.org/
Football Hooliganism in Europe 
Provides a historical overview and includes discussion of cross-national variations, media coverage, racism and alcohol.
http://www.sirc.org/publik/football_violence.html
Soldiers, Sashes and Shamrocks: Football and Social Identity in Scotland and Northern Ireland 
Extended article examining the extent to which clubs are used by various social groups for the expression of certain elements of their identities. Includes annotations and references.
http://physed.otago.ac.nz/sosol/v6i1/v6i1_1.html