April Carter 
Direct Action and Liberal Democracy [PDF ebook] 

This study focuses primarily on the nature of "direct action" in relation to contemporary movements, and considers the role of direct action methods in past campaigns for constitutional and social rights. Boycotts, sit-ins, obstructions, civil disobedience and other unconstitutional forms of protest are examined to see whether they necessarily lead to violence. The political conditions which encourage violence and the effects of various type of violent action are also discussed. The theoretical issues raised by direct action in a parliamentary system are also discussed.