Here’re the steps, to copy a document published using Google Docs, without edit permission:

One of the ways you could create a duplicate for the document is to replace

http://docs.google.com/View?docid=AAAAA
with
http://docs.google.com/DocAction?action=copy&docid=AAAAA
where AAAAA is the document ID.

Another idea is to upload the document to Google Docs, but you need to edit the URL to remove the footer and add the .html extension. Replace

http://docs.google.com/View?docid=AAAAA
with
http://docs.google.com/View?docid=AAAAA&hgd=1&.html

Or to automate the process, use this script that adds an option to duplicate the document. The script works in: Firefox with Greasemonkey, Google Chrome, Opera, Safari with GreaseKit, and Internet Explorer with IE7Pro. After installing the script, open the document, scroll to the bottom of the page and click on "Copy to my account".

Source:→ Google System