Internet Research. Bibliographic database. A bibliographic database may be general in scope or cover a specific academic discipline.
A significant number of bibliographic databases are still proprietary, available by licensing agreement from vendors, or directly from the indexing and abstracting services that create them. Many bibliographic databases evolve into digital libraries, providing the full-text of the indexed contents. Others converge with non-bibliographic scholarly databases to create more complete disciplinary search engine systems, such as Chemical Abstracts or Entrez.
History Prior to the mid-20th century, individuals searching for published literature had to rely on printed bibliographic indexes. See also Springer Realtime. Welcome to Sage. ACM Digital Library. Scopus. Home. Now in IEEE Xplore: The latest issue of IEEE Spectrum looking at the impact of lasers on motion pictures This issue explores how lasers will trigger the next great revolution in motion pictures.
More and more, people are watching movies on their laptops, tablets, and smartphones. In wealthy countries, middle-class homes are now typically outfitted with huge flat-panel TVs and powerful surround-sound audio systems. The upshot is that for many people, a trip to a movie theater is becoming a rare event, if not an increasingly distant memory. Learn how laser-based projection technology will make cinema screens bigger and brighter. » View the issue in IEEE Xplore. PubMed - NCBI. KNALIJ for Pubmed. Go Pubmed. Impact factor.
Calculation In any given year, the impact factor of a journal is the average number of citations received per paper published in that journal during the two preceding years. For example, if a journal has an impact factor of 3 in 2008, then its papers published in 2006 and 2007 received 3 citations each on average in 2008.
The 2008 impact factor of a journal would be calculated as follows: A = the number of times that articles published in that journal in 2006 and 2007, were cited by articles in indexed journals during 2008. B = the total number of "citable items" published by that journal in 2006 and 2007. ("Citable items" are usually articles, reviews, proceedings, or notes; not editorials or letters to the editor.) 2008 impact factor = A/B.
(Note that 2008 impact factors are actually published in 2009; they cannot be calculated until all of the 2008 publications have been processed by the indexing agency.) Use Criticisms Validity as a measure of importance Índice de impacto de las revistas españolas de ciencias sociales, IN-RECS, INRECS. JCR-Web 4.5 Welcome. Online Library. Books24x7. Learning Center. Safari Books Online - Home. 446 Places for Free Books Online. Introduction This is the launch page for the pages here at Gizmo's Tech Support Alert that list sites with free ebooks and audiobooks.
There are well over a million free ebooks and audiobooks at the sites listed within these pages. There are 3 pages that separate sites on the format of the ebooks, Kindle, ePub and Online Reading. There is a main page for both ebooks and audiobooks that lists all the sites carrying each. There are also 21 genre listings. The sites within the free comic books and free motion comics pages are not included in the main ebook and audiobook pages. To the best of my knowledge all of the websites listed here offer only content that they are legally entitled to transfer to you. To the best of my knowledge every website listed here, and its downloads, are safe. I hope you enjoy the content. Free eBooks & Audiobooks Complete Listings Best Free eBooks Online (913 sites) Best Free AudioBooks Online (224 sites) Free eBooks By Format Free Kindle eBooks Online Related Links. Online Search Tools.