This document provides information on why some materials may not be included in WorldCat and strategies for finding resources not listed in catalogs or databases. It discusses that libraries are not obligated to add all materials to WorldCat, such as rental collections or local historical materials. Tools for alternative searching like Google Books, Google Scholar, and government portals are presented. Challenges with locating newspapers, archival materials, and journal articles are addressed, along with interlibrary loan strategies and print/online resources for reference assistance.