A Bibliography is a list of resources on a topic. In the examples to the right, you could say that it is a "Book about books." Often a bibliography often includes a written summary about the book, called an annotation, telling the reader why the book is important to research on the topic. The books on the right contain lists of books on the history of Texas.
United States history a selective guide to information sources by 
United States history : a bibliography of the new writings on American history by