Please note: following the release of the new version of PubMed, the results returned by E-utilities queries of PubMed may differ slightly from those returned in the web version of PubMed. A new PubMed API is currently under development: more information will be announced when available.
As new Insider's Guide classes are no longer being offered, this site is not currently being updated. Please refer to NCBI's E-utilities documentation for more up-to-date information.
efilter command uses the History server to filter or restrict the results of a previous query.
This page is still under construction. For more information on
efilter, please see NCBI’s EDirect documentation page, “Entrez Direct: E-utilities on the UNIX Command Line”.