The National Library of Medicine^® (NLM^®) uses the ANSI/NISO Z39.29-2005 (R2010) Bibliographic References standard as the basis for the format of PubMed citations to journal articles. The National Information Standards Organization (NISO) is a non-profit association accredited by the American National Standards Institute (ANSI) to identify, develop, maintain and publish technical standards in the area of library and information science.

Guidance on the NLM interpretation of this national standard can be found in Citing Medicine: the NLM Style Guide for Authors, Editors, and Publishers, available via the National Center for Biotechnology Information (NCBI) Bookshelf.  

PubMed citations in the Summary (text) display format are compatible with ANSI/NISO Z39.29-2005 (R2010). This format is useful for a list of references or a bibliography. Here is a sample citation in the Summary (text) display format:

Freedman SB, Adler M, Seshadri R, Powell EC. Oral ondansetron for gastroenteritis in a pediatric emergency department. N Engl J Med. 2006 Apr 20;354(16):1698-705. PubMed PMID: 16625009.

The last element in the citation above identifies the unique identification number in PubMed (PMID).

The NLM citation format is also the foundation for the reference style approved by the Recommendations for the Conduct, Reporting, Editing and Publication of Scholarly Work in Medical Journals, a product of the International Committee of Medical Journal Editors (ICMJE). Please refer to Section IV.A.3.g.ii, References Style and Format, of the PDF version of the ICMJE Recommendations. The ICMJE Web site also lists the journals that follow the ICMJE Recommendations. NLM hosts and maintains a Web page featuring sample citations extracted from or based on Citing Medicine for easy use by the ICMJE audience.