I have a bibliographic record in RUSMARC (Russian UNIMARC) standard. For further processing I need to convert this record into MARCXML (MARC21 in XML) format.
How to accomplish such a tranformation programmatically?
UPDATE I have some routine to read and parse ISO 2709 format. However, RUSMARC (and UNIMARC in general) is different to MARC21 in terms of fields meaning.
UNIMARC records should be converted to MARC21 according to specifications published by Library of Congress (http://www.loc.gov/marc/unimarctomarc21.html).
First, you need to read your RUSMARC (UNIMARC) record into memory and construct XML according to UNISlim schema (http://www.rusmarc.ru/shema/UNISlim.xsd).
Then you can use XSL transformation that converts UNIMARC XML (in UNISlim schema) into MARCXML.
You can git this XSL transformation here: https://github.com/edsd/biblio-metadata