What is PubMed Central?
'''PubMed Central''' is a free [[Bibliographic database|database]] of [[science|scientific]] [[literature]] in biomedical and life sciences. It is on the Internet. It grew from the online [[Entrez]] [[PubMed]] biomedical literature search system. PubMed Central was developed by the [[United States of America|U.S.]] [[National Library of Medicine]] (NLM) as an online archive of biomedical [[journal]] articles. It was started in 2000.<ref name=Over /><ref name=Home>{{cite web|url=https://www.ncbi.nlm.nih.gov/pmc/|publisher=National Center for Biotechnology Information|accessdate=June 6, 2021|title=PMC}}</ref> As of 2021, it had over 7 million science papers in it.<ref name=Home/> All the words in the PubMed Central articles can be read freely. Some publishers, though, do not show their articles for some time after they publish them on paper (usually about six months). ==History== PubMed Central was started in 2000. At first, it only had papers from ''[[Proceedings of the National Academy of Sciences]]'' and ''[[Molecular Biology of the Cell]]''. People can add older papers to PubMed Central. The oldest papers in PubMed Central are from the 1700s.<ref name=Over>{{cite web|url=https://www.ncbi.nlm.nih.gov/pmc/about/intro/|title=PMC Overview|accessdate=June 6, 2021|publisher=National Center for Biotechnology Information}}</ref> As of September 2004, PubMedCentral, PubMed, and related NLM services had about 1,300 hits every second, and gave 1.3 [[terabyte]]s of data every day.<ref>[https://www.nlm.nih.gov/od/bor/bor904.pdf Minutes of the Board of Regents]</ref> The [[Library of Congress]] and the [[British Library]] showed support for the National Library of Medicine (NLM).<ref>[https://www.loc.gov/today/pr/2006/06-097.html News from the Library of Congress]</ref> It has also been popular with journal service providers.<ref>{{Cite web |url=http://www.inera.com/nlmresources.shtml |title=Inera NLM DTD Resources |access-date=2010-11-30 |archive-date=2013-02-19 |archive-url=https://web.archive.org/web/2013021904121