The best way to have a local up-to-date copy of all files is to setup a private mirror: See: the Mirroring How-To
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This is an example of how to get files using wget:
wget -w 2 -m -H "http://www.www.dfwtechs.com/robot/harvest?filetypes=html"
Replace html with the file type you are interested in.
If you want only files in a given language say:
wget -w 2 -m -H "http://www.www.dfwtechs.com/robot/harvest?filetypes=html&langs=de"
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