Searching for Holdings in Catalogues and Union Lists

Print holdings information and links from MARC 856 fields are available from catalogues and union databases that are accessible using Z39.50. It is also possible to construct URLs directly to a catalogue or union database if that is preferred.

Using Z39.50 to look for records in a catalogue or union database allows for better retrieval of records than simply constructing a title or ISBN/ISSN based URL. GODOT retrieves records via Z39.50 and then filters the records to remove those that are not a good enough match. The filter process includes normalizing titles, ISBNs and ISSNs and then comparing them to normalized citation data. For details on this filtering process, please see GODOT On-the-Fly Matching Algorithm.

Retrieving bibliographic records via Z39.50 is reasonably straightforward and is similar for most vendors. However, the procedure required to retrieve good item and circulation level information from different Z39.50 servers varies considerably. The ILSs for which details of item and circulation level retrieval have been worked out are Aleph, Endeavor, III and Sirsi.