Classification 28 Books 24 Subject cataloging 24 Subject headings 19 Indexing 11 Information organization 9 Cataloging 8 more ... Subject access 8 Online library catalogs 6 Bibliography 5 Classification, Dewey decimal 5 Information storage and retrieval systems 5 Subject headings, Library of Congress 5 Classification, Library of Congress 4 Information retrieval 4 Online bibliographic searching 4 Abstracting 3 Classification of sciences 3 Methodology 3 World Wide Web 3 Categorization (Psychology) 2 Data mining 2 Data processing 2 Descriptive cataloging 2 Knowledge, Sociology of 2 Library materials 2 Logic 2 Machine-readable bibliographic data 2 Metadata 2 Psychological aspects 2 less ...