The University of Delaware uses the Library of Congress Classification System, which groups books together by subject. The different subjects are given a corresponding letter. Here's how it works:
D: History (General)
DS: History of Asia
DS520 to DS560.72: History of Southeast Asia
DS558.6.S644 G93 2010: Southeast Asia and the Vietnam War by Cheng Guan Ang
If you're interested in researching the history of China, the call numbers range from DS701 to DS799.9. For the history of Japan, it ranges from DS801 to DS897, and for the history of Korea, the call numbers range from DS901 to DS937. For a discussion of political institutions and public administration in East Asian countries, look at the call numbers between JQ1499 to JQ1749.
This is just a sampling of the subjects that you might encounter. Because Asian Studies is so interdiscipliary, you may need to do a specific subject search in DELCAT Discovery, the library's catalog, to find the call number for the book that you need.
For more information about how to locate a book in the library using a call number, please see the ENGL110 class page on Finding Books.