The library collections are accessible online in the Regensburger Katalog (OPAC). The search in older collections is only possible in the alphabetic and subject card catalogues. The Leibniz Institute for East and Southeast European Studies is currently cataloguing the articles of more than 100 scientific journals and documents the data in osmikon. It also provides the data of articles of several journals in the gateway IREON. Lines of descent of foreigner families in Russia from Amburger-Archiv are available on the PCs in the reading room. The library is connected to interlibrary loan (ISIL: DE-Re13). The Institut für Ostrecht documents the journals and collections of jurisdiction of several Eastern European countries. These materials are catalogued according to a special classification. The catalogues are accessible in the rooms of the country referents.