The paper describes an approach to improving classification-based subject access in a library catalogue. In order to enhance the use of UDC numbers in information retrieval, the authors have represented classification with thesaurus descriptors and implemented this solution in an automated way. In addition, descriptors in more than one language were used to interface classification. The authors present a solution implemented in a BiblioPhil library system. The standard formats used are UNIMARC for bibliographic and subject authority records (i.e. the UDC-based multilingual thesaurus) with MARCXML support for data transfer. The multilingual thesaurus was built according to the existing standards, the constituent parts of the classification notations being used as the basis for search terms in the multilingual information retrieval. The verbal equivalents, descriptors and non-descriptors, are used to expand the number of concepts and are given in Romanian, English and French. The authors illustrate how this approach saves the time of the indexer and provides more user-friendly and easier access to the bibliographic information. The multilingual aspect of the thesaurus enhances information access for a greater number of online users.