Guide to Materials of Dianetics and Scientology, published in 2009 by the Church of Scientology Internationsl. This is a book which purports to highlight all the various books, lecture series and other materials from the Church. For the most part, it shows each item in chronological order and explains the item in its proper context. As such, it is a useful tool to use as a jumping off point in researching the chronology of the subject. Its chronology is assumed to be accurate. Where a reader has disagreement, they are encouraged to contact The History and make their case (preferably with supporting evidence) about a particular citation.