Subject headings are often very broad.
No subject headings are assigned to Government Publications. Journals, many yearbooks and most microfiche collections are included only under the author and title of the journal, yearbook series or microfiche set, and under 1 or 2 broad subject headings for the journal, series or set. Individual articles within journals are not indexed, as are not many yearbooks within a series or individual titles within many microfiche collections. Keyword searching capability is provided. Keyword searches should incorporate controlled vocabulary.