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Locating Books by Call Number: Home

Locating Books by Library of Congress Call Number

What's a Call number?

Call numbers are book shelf addresses, unique to a single book and indicate where a book is located in the library. All books are arranged alphabetically by the beginning letters of their call numbers. You will find the call number attached to or written on the spine of each book.

The Alkek Library uses Library of Congress call numbers that uses letters and numbers to arrange books by subject. Books on similar subjects are assigned similar letters, based on the Library of Congress call number system.

A: General Works M: Music and Books on Music
B: Philosophy. Psychology. Religion. N: Fine Arts
C: Auxiliary Sciences of History P: Language and Literature
D: History: General & Old World Q: Science
E: History: America R: Medicine
F: History: America S: Agriculture
G: Geography. Anthropology. Recreation      T: Technology
H: Social Sciences U: Military Science
J: Political Science V: Naval Science
K: Law Z: History of Books. Library Science. Bibliography.
L: Education


To locate a book in the Alkek Library, make note of the:

  • Location/Floor
  • Call Number
  • Status (whether the book is Available or checked out)


Areas where many books are located in the Library:

Understanding Call Number Order


Library of Congress call numbers should be read one line at a time as follows:

Example of a complete call number, DA 36 .A55:

DALine 1
 36 Line 2
 .A55Line 3

1.  First, look at Line 1:

Books are arranged in alphabetical order, by the letters on the first line of the call number.

Example: first come all the D call numbers, then the DA call numbers, then DB, etc.

2.  Next, look at Line 2:

Within the DA call numbers, books are arranged in number order.
The numbers are arranged in numerical from low to high.

3.  Then look at Line 3:

Line 3 of the call number has a letter and a number. The letters are in alphabetical order.

Then read the numbers as DECIMAL numbers, not whole numbers.  

Example: A55 is read as A .55 - this is why A55 comes before A6 (A .55, A .6, A .65, etc.)


Call numbers beginning with lettersLocated on:
A through J Floor 5
K through Q Floor 6
R through Z Floor 7


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