Columbia subject headings:
Essex (England)--Antiquities.
Essex (England)--History.
Industries--England--Essex.
Natural history--England--Essex.
Harvard subject headings:
Essex (England)--Antiquities.
Essex (England)--History.
Industries--England--Essex.
Natural history--England--Essex.
Princeton subject headings:
Essex (England)--Antiquities.
Essex (England)--History.
Industries--England--Essex.
Natural history--England--Essex.