The Stanford Encyclopedia of Philosophy (SEP) is a freely-accessible online encyclopedia of philosophy maintained by Stanford University. Each entry is written and maintained by an expert in the field, including professors from over 65 academic institutions worldwide. Authors contributing to the Encyclopedia give Stanford University the permission to publish the articles but retain the copyright to those articles. As of November 2008, the SEP has over 1000 published entries. Apart from its online status, the encyclopedia uses the traditional academic approach of most encyclopedias and academic journals to achieve quality by means of: