There are three Boolean operators:
Or means that items in the search results can contain either (or both) criteria. For example, searching for the electronic vendor "Lexis-Nexis" or "Ovid" would return titles that are available in an electronic format (such as CD or online) from either Lexis-Nexis or Ovid.
Andnot means that items in the search results must contain the first term but not the second.
cc=united states and ev=catchword would find all citations from a U.S. publisher available from Catchword.
mc = microfiche and su=sciences would retrieve all citations that are available in microfiche form that are clasified under the subject category "sciences".
mc=tabloid or newspaper would retrieve all citations that are available in tabloid or newspaper format
mc=talking or record or audio would retrieve all citations that are available as a talking book, record, or audio cassette
Pn=jones, tom or pn=smith, sam will return citations that have either Tom Jones or Sam Smith as an editor or other personnel contact name.
su=business and ev= NewsNet would find all citations in this subject area that are available as online service from NewsNet.
su=computers and st=NJ will return computer titles published in New Jersey.