Box 59Both a date of update/revision and a date of citation

Various words are used to show that the content of a database/retrieval system has been changed. Among them are: updated, modified, revised, reviewed.

  • Begin with the date(s) of update/revision in the format year month day
    • Use the wording for update/revision supplied in the database/retrieval system
    • Give all words with the dates provided, in ascending date order. For example:
      • reviewed 2004 Sep 1; modified 2006 Aug 17;
    • Separate words by a semicolon and a space
    • End the date(s) of update/revision with a semicolon and a space
  • Enter the date cited in the format year month day
  • Place all dates of update/revision and the date of citation in one set of square brackets
  • End with a period placed outside the closing bracket
    • Health Library for Disasters [Internet]. Version 3.0. Geneva: World Health Organization. 2003 -   [updated 2006 May; cited 2007 Feb 1]. Available from:
    • Rotchford JK, editor. [Internet]. Port Townsend (WA): Best of Both Worlds Foundation. [date unknown] -   [modified 2006 Jul; cited 2007 Feb 1]. Available from:
    • Database of Human Disease Causing Gene Homologues in Dictyostelium Discoideum [Internet]. San Diego (CA): San Diego Supercomputer Center; 2003 [modified 2003 Mar 30; cited 2007 Feb 2]. Available from:
    • Cornell University Poisonous Plants Informational Database [Internet]. Ithaca (NY): Cornell University, Department of Animal Science. [date unknown] -   [updated 2006 Oct 27; cited 2007 Feb 1]. Available from:

From: Chapter 24, Databases/Retrieval Systems on the Internet

Cover of Citing Medicine
Citing Medicine: The NLM Style Guide for Authors, Editors, and Publishers [Internet]. 2nd edition.
Patrias K, author; Wendling D, editor.
Bethesda (MD): National Library of Medicine (US); 2007-.

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