Electronic articles are articles in scholarly journals or magazines that can be accessed via electronic transmission. They are a specialized form of electronic document, with a specialized content, purpose, format, metadata, and availability-they consist of individual articles from scholarly journals or magazines, they have the purpose of providing material for academic research and study, they are formatted approximately like printed journal articles, the metadata is entered into specialized databases, such as the Directory of Open Access Journals as well as the databases for the discipline, and they are predominantly available through academic libraries and special libraries, generally at a fixed charge. Electronic articles can be found in online-only journals, but in the 21st century they have also become common as online versions of articles that also appear in printed journals. The practice of publishing of an electronic version of an article before it later appears in print is sometimes called epub ahead of print, particularly in PubMed. The term can also be used for the electronic versions of less formal publications, such as online archives, working paper archives from universities, government agencies, private and public think tanks and institutes and private websites. In many academic areas, specialized bibliographic databases are available to find their online content. Most commercialsites are subscription-based, or allow pay-per-view access. Many universities subscribe to electronic journals to provide access to their students and faculty, and it is generally also possible for individuals to subscribe. An increasing number of journals are now available with open access, requiring no subscription. Most working paper archives and articles on personal homepages are free, as are collections in institutional repositories and subject repositories. The most common formats of transmission are HTML, PDF and, in specialized fields like mathematics and physics, TeX and PostScript.
