... of making many books there is no end ... (Eccl. 12:12)
Reserouces and seraching guides at other libraries may provide valuable help - especially when seraching for materials pertinent to Jewish history in that particual country. Search in REX to check if a resrouce is available here; if not, try inter-library loan.
Libraries at Copenhagen University
Carsten Niebuhr Afdelingens bibliotek (Danish) - only for use on-location
University libraries in Denmark, whose book can be made available within Denmark through bibliotek.dk
Statsbiblioteket, Århus
Syddansk Universitetsbibliotek
Libraries abroad
Lunds Universitetsbibliotek - partner in the Oresound agreement!
Göteborgs Universitetbibliotek
Uppsala Universitetsbibliotek
Umeå Universitetsbibliotek
Åbo Akademi
The National Library of Finland
COPAC (union catalogue for all British univeristy librarires and the British Library)
Die deutsche Bibliothek
Bibliothéque Nationale de France
Bibliotheca Rosenthaliana (special Judaica collection UB Amsterdam)
The Vatican Library has made its Hebrew Manuscripts catalogue available as a PDF-file.
Jewish National and University Library
Israel Union List
Library og Congress
New York Public Library
Harvard University Libraries
Princeton University Library
Stanford University Library - which also has an excellent page with an overview of online recources
... to only mention a few of the U.S. libraries
Worldwide directory to e.g. libraries
Academic Jewish Studies Internet Directory
Academic Libraries and Archives on the Net
Happy hunting!