Columbia subject headings:
Copyright licenses--United States--Data processing.
Library of Congress. Copyright Office--Appropriations and expenditures.
Library of Congress. Copyright Office--Data processing.
Harvard subject headings:
Copyright licenses--United States--Data processing.
Library of Congress. Copyright Office--Appropriations and expenditures.
Library of Congress. Copyright Office--Data processing.
Princeton subject headings:
Copyright licenses--United States--Data processing.
Library of Congress. Copyright Office--Appropriations and expenditures.
Library of Congress. Copyright Office--Data processing.