From this page you can export the Library records in standard MARC communications format (ISO2709).
Only the basic bibliographic information is exported. No holdings information is exported apart from any holdings information originally loaded into Koha using the bulkmarcimport tool.
Add a starting biblio record number and an ending number.
Leave the start and end numbers blank.
Records are downloaded to the workstation that the export was requested from. The filename will be “marc.pl.”