GVRL is a collection of online books that you can search all at once. There books here are on a wide range of topics, not just communication topics. This is useful for getting background information on historical events or topics that may have a non-communication dimension, such as health issues or political issues.
Coverage of "controversial issues in a straightforward, nonpartisan primarily pro-con format." Areas covered include business, health and medicine, law, politics, religion, science and technology, sex and gender, and sports.