Translation:The Austrian writer writes only in Polish.
There could be many reasons. (or perhaps its just a constructed sentence).
But if you take a look at this wikipedia page - (it's in German) you find 70 different (more or less famous) Austrian people who were born/or lived in the city of Lwiw (a Polish city- one of many others in Poland).
You can verify that by searching for österreichisch (which means Austrian in German).
Some of them were authors and it wouldn't surprise me if one of them had chosen to write only in Polish for some personal (or economic or whatever) reason.
But perhaps, as I said, could be that it's only a constructed sentence from an algorithm....
my first thought was Asterix :) http://ihackedgames.net/wp-content/uploads/2015/11/asterix-friends-online-hack-generator-tool.png