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AMA 11th Referencing Guide

Referencing guide for the 11th Edition of AMA Style

Date unknown

You should always try to find a date for your sources.  Most reliable sources of information will have a date - either a date for when the source was published, or a date for when it was last updated.

For books:

If you genuinely cannot find a date, and you must cite this work, use "date unknown" in place of the year.

  1. Brown B. Self published books are the future of science. Brown's Own Books; date unknown.

For websites:

If you genuinely cannot find a date, and you must cite this work, omit published date and use the updated date and date accessed.

  1. Smith J. Carrots can cure everything.  Carrots Marketing Corporation. Updated June, 2014. Accessed May 25, 2015.
  2. Jones L. Spinach makes you strong. Vegetable Marketing Queensland. Accessed September 10, 2020.

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