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Finding Books Help Guide

Finding Books in a Library

The catalog tells you whether or not we have an item. If we have the item, the catalog will give you the item’s call number.  Each item has a unique call number which is the item’s address.

A call number is a code made up of a series of numbers and letters. We use the Library of Congress Classification System to create a call numbers, which ensures that you can find the books you need.

This is what a call number looks like in the catalog:

This is what a call number looks like on the book:

All those letters and numbers mean something. And while it can be useful to know what they mean, it’s more important to know how they work. A call number is the book’s address.

To find books on the shelf, read call numbers line by line. Take the call number: AG105​.B553​ 1987

  1. Start with the first line - the letters, and search for the correct section of that letter in the stacks. The letters go in alphabetical order. A is before B, AC if still before B.
  2. The second line is all numbers. They should be read as whole numbers.
  3. The third line is a combination of letters and numbers. The letters are read in alphabetical order, but the numbers are read as decimals. This means the longer number isn’t always last. Since it’s a decimal, the longer number might be smaller. For example,. .B65 vs. .B553 -  65 is smaller than 553, but that’s not what we are looking at. We have here .65 and .553, so .B553 would be first.  Some call numbers have more than one combination letter-number line, so watch out for that.
  4. The final line is a four-digit number - it’s always the year the book was published. Read it in chronological order.

Related books are often near each other, so once you’ve found what you are looking for, feel free to take a moment to look around and see if there’s anything that might be useful to you.

UDC Search


UDC Search is the catalog search at UDC. Through this single search box, you can find books, articles and other materials owned by the UDC library, and other libraries in the Washington Research Library Consortium. 

Start your search using the search box above. This is also found on our library homepage.

Once you perform an initial search, you will be presented with filters on the left-hand side that will allow you to narrow your search.

You can also change what you are searching for, using the dropdown menu next to the search bar.

  • Everything means you are searching at UDC and WRLC
  • UDC Library Catalog means, only physical or electronic resources available at UDC
  • Articles is if you specifically want to search for articles, not books
  • Course reserves allows you to search for books available on reserve (circulating for 2 hours)
  • Digital Collections - Learning Resources Division will show you digitized items from the UDC Archives

This video will walk you through using UDC Search:


E-books are books, too! They just happen to be available to you online. Just like any of the library's databases, these can be used from anywhere with an Internet connection. When prompted, all you have to do is log-in using your UDC credentials. 

Many e-books may be downloaded (chapter-by-chapter or the entire book) and some can even be printed. If you check out an e-book, it will "disappear" from your library account on its due date.

E-books are available in many of the library's databases. You can try a few of them in the list below:

Something Missing?

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The library is always open to adding missing content to our guides. We are happy to add new links, information, and resources you may be aware of. Please email us at to share any links or information you would like to see us include.