(Seen in Carl Schorske’s Fin de Siècle Vienna, page 126 fn.) It’s in Vienna so presumably they’re Austrian, not “German.” Does it mean “German-speaking”? Was it a nationalist thing (i.e., deutsches Volk as opposed to other nationalities in Vienna)?
Here’s a contemporary reference: https://reader.digitale-sammlungen.de/de/fs1/object/display/bsb11315525_00005.html
In Gasser's Nietsche und Freud the following explanation is given:
"Der 'Leserverein der Deutschen Studenten Wiens' soll den geistigen und geselligen mittelpunkt der deutschen studenten an den Wiener Hochschulen mit auschluss jedes politischen charakters bilden".
Translated:
"The 'Readers' Association of the German Students of Vienna' is intended to form the intellectual and social center ofGerman students at the Viennese Universities with the exclusion of any political character."
The association was nominally for German students studying in Vienna and had some world-renowned thinkers amongst its ranks.