Is being able to work in a university library as a member of the public standard practice in Germany? (Or is the poster an alumnus, perhaps?) I'd love to do that here in the UK but they're key-carded to the hilt.
I can't speak for Germany, but in the United States practices vary. You can't just walk into the library at the University of Wisconsin, but at North Carolina State you can.
When I lived in Washington State, I had no particular connection with U Dub, but I could also walk onto campus and walk into the library shelving areas with no problem. When I wanted to circulate books, I looked up the state administrative regulations (it helped that I was working as a lawyer, so I knew how to look those up) and found out that a state regulation basically allows most state residents to obtain circulating privileges at University of Washington libraries for the payment of a small fee. That library has a GREAT collection of materials on east Asian languages, and I circulated some of those while I was living in Washington state.