OU Libraries uses the Library of Congress classification system for almost all of its holdings. When you know Library of Congress subject headings you can perform very precise searches in our catalog and other databases. Some subject heading structures that may be useful include:
Note that you do not have to use diacriticals when entering your search terms.
To find write, writer, written, or writing, enter the letters common to all forms, writ, and add the truncation symbol (e.g., writ*). Frequently the truncation symbol is an asterisk (*), though it might be a different character. A database usually has search tips or a help page explaining its symbols.
For example, if the wildcard symbol is a question mark (?), typing wom?n will return results containing the word woman or women. You can also use a wildcard to pick up variations in spelling: reali?e will find both realize (American spelling) and realise (British spelling).
When you want to ensure that words remain together in a particular order, use phrase searching. Most often, phrase searching is accomplished by placing the search terms in quotation marks. “Comedy of manners” will produce records where those three words appear as a phrase.
To ensure that your search is understood by the computer, you can use nesting, a technique by which you can group operations using parentheses. The nesting parentheses in a search string work much the same way as they do in mathematical equations. The result of 5 + 12 ÷7 - 4 is different from that of (5 + 12) ÷ (7 - 4). We can make the database understand what we want by using nesting. Like Ukranian Matryoshka dolls, nesting places one thing—in this case, one search statement—within another. To control how your search terms are understood, place parentheses around the elements: "german*" and (expressionism or modern*) and (drama or theat*).