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Understanding Call Numbers: How do I use call numbers?

A guide to the Library of Congress call numbers used at Geisel Library.

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At Geisel Library, books in the General Collection can be found as follows:

  • Call Number A - DK: Main Level
  • Call Number DK - TX: Upper Level
  • Call Number U - Z: Lower Level

Step One

When you find an item of interest in Library Catalog, write down its call number and be sure to note the item's Location:

  • Upper Level - General collection, Oversize, Archives & Special Collections
  • Main Level - General collection, Reading Room, Reference, CTE, Atlases
  • Lower Level - General collection, Periodicals, Government documents, VHS & DVDs, CD/Music, Education, Games, Indexes, Catholic, Microform

Step Two

Head to the area of the library where your book of interest is shelved.  Use the signs at the end of every shelving range to determine which row will house your book.

Once you identify the correct row, you can find the book by using your knowledge of how call numbers are ordered on the shelf.  The key is to hone in by finding the books that match each successive part of the desired book's call number: first the initial letter(s), then the number, and so on.

For "Guns Germs and Steel", start by finding the books whose call numbers start with HM, then browse numerically to the HM206 books.  Once you're there, browse alphabetically up to the .D, then browse decimal-wise to .D48.  You'll find your book waiting for you there (if it's not checked out!).