Tools for Verifying
Bibliothèque nationale de France
Book and Serial Vendors for Africa and the Middle East
Book and Serial Vendors for Asia and the Pacific
The British Library
CATNYP--Catalog of the New York Public Library
Center for Research Libraries
HOLLIS--Harvard OnLine Library Information System
LibDex--Library Index
Library of Congress
Measuring Units Conversion Table
Melvyl--Catalog of the University of California Libraries
National Geographic Map Machine
OCLC--The Online Computer Library Center
Roman Numeral Converter
UNESDOC/UNESBIB--bibliography of UNESCO documents and publications and Library collection
Universal Currency Converter