Originally Posted by vice-versa
I'm not sure to find really something to my taste in German in project Gutenberg
Your taste must be delicate indeed. If I were to test whether the G-E dictionary is principally working I would take any German language book at hand. Of course, it is different if you would like to test the quality of the dictionary. Judging from the file size it is rather small.
You can find a greater variety of free German ebooks at http://gutenberg.spiegel.de/
. With the help of http://www.epub2go.eu/
you can convert them to epubs.