Help in all areas of subject access is available through these tools. Published in various formats, the major subject headings authority tools listed here are included in either Classification Web (http://www.loc.gov/cds/classweb) or Cataloger's Desktop (http://www.loc.gov/cds/desktop). Both are web-based subscription services and both offer free 30-day trials.
- Free-Floating Subdivisions: An Alphabetical Index
- LC Period Subdivisions Under Names of Places
- LC Subject Headings Weekly Lists
- Library of Congress Subject Headings
- Library of Congress Subject Headings
- Library of Congress Subject Headings Supplemental Vocabularies: Free-Floating Subdivisions, Genre/Form Headings, Children's Subject Headings
- SACO Participants' Manual
- Subject Headings Manual
