The library catalog and WorldCat use Library of Congress Subject Headings. The list of authorized subject headings is available online from the Library of Congress Classification/Subject Headings database. However, you can also start with keyword searches to gather some relevant titles, then look at their subject headings to discover the official terms to use.
Case does not matter. Punctuation marks are not needed.
Keyword searches will likely retrieve something on your subject. This type of search looks in practically all parts of the catalog record, and is the only way to access the data in the Contents Notes field of records. However, if you are not using the terms catalogers use to identify a subject, keyword searches may actually retrieve fewer items than a subject search.
Subject searches use a controlled vocabulary, bring more consistency to searches and organizing records by subtopics. Library of Congress Subject Headings are used in both the local catalog and in WorldCat. Even if Randall Library does not have books listed in the catalog under these headings, you will find them in WorldCat (and perhaps in other databases using LC Subject Headings.)
The Library of Congress Subject Headings for the Korean War include:
Korean War, 1950-1953 (many subdivisions provide specifics)
Narrower terms are:
Chipyong-ni, Battle of, Chipyong-ni, Korea, 1951
Imjin River, Battle of the, Korea, 1951
Inchon Landing, Inchon, Korea, 1950
Kochang Incident, Korea, 1951
Naktong Bulge, Battle of the, 1950
Operation Big Switch, 1953
Operation Little Switch, 1953
Tabu-dong, Battle of, Korea, 1951
These related terms may also yield relevant sources:
Korean Demilitarized Zone (Korea)
Korean reunification question, 1945-
War poetry, Korean
War stories, Korean
Vietnam War, 1961-1975 (many subdivisions provide specifics)
[name of battle or operation]
My Lai Massacre, Vietnam, 1968
Son Thang Incident, Vietnam, 1970
Tonkin Gulf Incidents, 1964
Vietnam -- History -- 1945-1975
Other related headings:
United States -- History --1945-1953 or 1961-1969
United States -- Foreign relations -- 1945-1953 or 1945-1989
United States -- Politics and government -- [various chronological periods since 1945]
Also consider keyword searches on personal names relevant to the Korean or Vietnam War. Typically, names are entered with the last name first, e.g., MacArthur, Douglas. Do both Author and Subject searches to find books by and about the individual.