Columbia subject headings:
Citation indexes.
Humanities--Abstracting and indexing.
Science--Abstracting and indexing.
Technology--Abstracting and indexing.
Harvard subject headings:
Citation indexes.
Humanities--Abstracting and indexing.
Science--Abstracting and indexing
Technology--Abstracting and indexing
Princeton subject headings:
Citation indexes.
Humanities--Abstracting and indexing.
Science--Abstracting and indexing.
Technology--Abstracting and indexing.