Books and articles on specific subjects can be found in the databases in three ways:
Search by means of ordinary words. In these searches one, or more words, are used, for different aspects of the subject combined with "and", or different synonyms for the same subject (aspect) combined with "or" – or a combination of the last two. The method can be used in all databases, including REX, bibliotek.dk and international bibliographic databases. The method is suitable in connection with broad or imprecise searches and in situations, where it is possible to make a precise search by using a small number of specific terms.
The search is normally done in such a way, that the word used for searching will be looked for in titles, series titles, tables of content, abstracts, and among the descriptors etc. In most international bibliographic databases English or American words are used to find publications in all languages. In other databases words in other languages must be used to find publications in these languages, as is the case in REX and bibliotek.dk.
Search by means of the specific descriptors, that may be contained in the records. In searches one word is used, or different words for different aspects of the subject combined with "and", or different synonyms for the same subject (aspect) combined with "or" – as described above. The method can be used in many databases, including REX, bibliotek.dk and most international bibliographic databases. The method is suitable in connection with searches, that are neither broad nor narrow, and where a few specific terms for the subject does not exist.
Normally the descriptors include place names - and in some of the databases the descriptors can be found and searched by using a specific dictionary (THESAURUS). International bibliographic databases normally contain descriptors in English or American – but REX contains descriptors in English/American and Danish, and bibliotek.dk contains descriptors in Danish. In some databases the subject words are not called descriptors, but keywords etc.
Search by means of the specific codes (classification codes), that may be contained in the records. In searches one code is normally used, several codes can be combined with "or", and in some cases two or three codes can be combined with "and" - as described above. The method can be used in some databases, including REX, bibliotek.dk and some international bibliographic databases. Different databases contain one or several different types of codes.
REX contains different types of codes, and some of these include codes for places. However, only some books (not all) can be found by the use of codes (of a specific type). With these reservations the method is suitable in almost the same situations as descriptor search.