Columbia subject headings:
Reference books--Bibliography.
Reference services (Libraries)--Handbooks, manuals, etc.
Research--Handbooks, manuals, etc.
Harvard subject headings:
Reference books--Bibliography
Reference services (Libraries)--Handbooks, manuals, etc.
Research--Handbooks, manuals, etc.
Princeton subject headings:
Reference books--Bibliography.
Reference services (Libraries)--Handbooks, manuals, etc.
Research--Handbooks, manuals, etc.