Since 1985, the "Britannica" has had four parts: the "Micropædia," the "Macropædia," the "Propædia," and a two-book index. The "Britannica"'s articles are found in the "Micropædia" and "Macropædia," which contain 12 and 17 books, respectively, each book having about one thousand pages. The 2007 "Macropædia" has 699 detailed articles, which can be as short as 2 pages and as long as 310 pages, and having references and named writers. The 2007 "Micropædia" has about 65,000 articles, and about 97% contain less than 750 words, no references, and no named contributors. The "Micropædia" articles are supposed to be for quick fact-checking and to help in finding more information in the "Macropædia". The "Macropædia" articles are supposed to be well-written articles on their subjects and articles of information where you cannot find anywhere else. The longest article (310 pages) is on the United States, and came from putting the articles on the individual states together.