The Fourth Edition of AN INDEX TO OXFORDIAN PUBLICATIONS includes more than three thousand new listings, for a total of more than 9,000 entries (an increase of 50% over the 2015 Third Edition), including new sections that expand its already extensive coverage of all Oxfordian publications over the past 95 years. The INDEX's periodical coverage includes current titles (The Shakespeare Oxford Newsletter, Brief Chronicles, The Oxfordian, and The De Vere Society newsletter) through the end of 2016, plus full coverage of all past publications from both independent publishers and older Oxfordian societies, such as The Shakespeare Fellowship Newsletters (both the English and American branches, 1930s to 1950s), Shakespeare Matters, The Elizabethan Review, The Spear-Shaker Review, The Edward de Vere Newsletter, The Shakespearean Authorship Review, and The Bard. In addition to updating all current periodicals (newsletters and journals), and filling in the gaps where older records had been incomplete before, the INDEX now includes more than 2,500 articles, book reviews and letters to the editor from more than 200 non-Oxfordian publications that have reviewed and commented on the Oxfordian theory since 1920. These include the regular Oxfordian columns that appeared in Louis Marder's Shakespeare Newsletter (1979-1991) and The Shakespeare Pictorial (1929-1939), as well as others ranging from The Los Angeles Times, The New York Times, The Washington Post, Harper's, Atlantic Monthly, Shakespeare Quarterly, and Notes & Queries to newspapers, magazines and smaller literary reviews from around the world. Finally, the INDEX has been expanded to include an extensive bibliography of every Oxfordian book published since 1920, along with selected non-Oxfordian books on the Shakespeare authorship question in general. There are separate sections on the books themselves, and where authors have published both books and articles, all entries are also grouped together under the author's name in the main index. The 350 listings in the new book section include both nonfiction commentary and criticism, and also fictional works inspired by the Shakespeare authorship question, particularly the Oxfordian thesis.