Columbia subject headings:
Election districts--United States--Maps.
Maps.
United States. Congress. House--Election districts--Maps.
Harvard subject headings:
Election districts--United States--Maps
Maps
United States. Congress. House--Election districts--Maps.
Princeton subject headings:
Election districts--United States--Maps.
Maps.
Thematic maps.
United States. Congress--Election districts--Maps.
United States. Congress. House--Election districts--Maps.