Register now or log in to join your professional community.
OCLC classify
check this site you can search by author, keyword or title.
My top two preferences:
Library of Congress Online Catalog: https://catalog.loc.gov
OCLC WorldCat: https://www.worldcat.org/
serial nos and your cataloging system is the best way to find your books.
A useful site which could get you call number of books faster is usually The Library's Research Help Page or the Resources for Undergraduates Page or Graduates Page which ever one you prefer.
For Library User Visit the Library Catalogue (OPAC). For professionals, there are lots of Sites for example. www.chopac.org (free), Classify.oclc.oeg (Free), Classificationweb.net (Subscription ) etc..
Library of Congress: http://catalog.loc.gov
OCLC WorldCat: http://www.worldcat.org
OCLC CLASSIFY for class number and CATALOGUING CALCULATOR for cutter number.
to dewy classification DDC cuter number