Expert Search (formerly called Command Keyword) is the most powerful search method available
for the Library of Congress Online Catalog. Use this search method
to retrieve items with selected words or phrases located anywhere
in the catalog record. Expert Search may be used for a simple
single-word search, but it also allows for more complex searches
that combine multiple terms from one or more fields of a record.
|Expert Search allows for
more complex searches using Boolean
operators and special index codes.
Search limits are available for Expert Searches. Boolean operators (AND, OR, NOT) may
be used with or without parentheses and special
index codes may be used to focus the search.
Expert Search Examples:
|To retrieve . . .
||Enter the search string . . .
|materials on missions to Mars or Venus
||(mars OR venus) AND mission
|materials by and about Brian Aldiss
|| knam "aldiss brian"
|catalog record for LC Control Number (LCCN) 98-1
|ISSN 1094-1304 (Journal of Health care marketing)
|ISBN 0-553-37783-3 (Amazing Colossal Episode Guide)
|name Chaucer anywhere, published by Oxford University Press
||knam chaucer AND 260b "oxford university"
|proceedings of the Grand Chapter of the California Royal
||k110 "royal arch masons" AND california
|materials having the class number gv946 published in London
||kcla gv946 AND 260a london
|printed music of songs used at Olympic Games
||set search limits Type of Material: Printed Music
ksub olympic? AND ksub songs
|information about building canoes or kayaks but not with
||(skey canoes OR skey kayaks) AND skey design NOT skey
- Set search limits before constructing
- Use ? at the end of a search word for truncation (e.g.,
ecumen? will search for ecumenical, ecumenism,
- Enclose exact search phrases in quotation marks (e.g., "tax
reform"). Truncation may be included within quoted phrases
(e.g., "afr? american").
- Combine several terms using Boolean operators:
AND, OR, or NOT. Boolean operators may be
entered in upper or lower case.
- AND - narrows the search by combining
multiple concepts (e.g., mars AND mission)
- OR - broadens the search with related
terms for each concept (e.g., ten OR 10)
- NOT - excludes terms from the search
(e.g., marketing NOT sales) Note: use
caution when selecting the Boolean NOT operator so
that desired catalog records are not inadvertently excluded.
- If you want to include the words and, or
or not as search words, it is necessary to include
them, along with other words in quotes as a phrase.
- Combine several Boolean operators in a single search statement,
using parentheses to group concepts together.
Example: (wood? OR forest) AND "resource manage?"
- Restrict search words or phrases to a particular index (or area
of the catalog record), by preceding them with the appropriate
Index Code prior to the search word
or phrase (e.g., ktil five AND kpnc lewis).
Alternative Search Options:
To build searches from fill-in-the-blank boxes, using Boolean
operators and index codes from drop-down menus, try Guided Search.
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