"Discourse and Contemporary Social Change" (2007): In this book, Fairclough discusses how language and discourse play a role in social change. He explores the concepts of representation, action, and identity in detail. That's my all-time favourite. Many journal articles explore Fairclough's concepts within CDA. You can search academic databases like JSTOR or Google Scholar for articles that specifically focus on these concepts. Look for articles by Norman Fairclough or scholars who build upon his work, such as Ruth Wodak, Gilbert Weiss, and Michael Meyer.