Google Scholar: a citation enhanced database

[A K Sharma]

Google scholar (released in Nov 2004) in beta version is freely available service that link the wide variety of sources. Google scholar covers journals, books, conference proceeding, dissertation, technical reports, preprint and post prints and other scholarly document from all area of science

Some prominent collection includes Association for computing Machinery, ArXiv, Bio-Med central, blackwell, High wire press, IEEE, Ingena Connect, NASA Astro Physics Data System, Pubmed, Nature Publishing Group, RePEc, Springer, Wiley Inter Science, these sources are, however, not all indexed entirely and some major publishers including Elsevier and American chemical Society have decline to cooperate with Google Scholar.
However, GS(Google Scholar) has potential to become more comprehensive than any single bibliographical database

need some comments with more detail of GS