Columbia subject headings:
Agriculture--England--Northamptonshire--History.
Northamptonshire (England)--Antiquities.
Harvard subject headings:
Agriculture--England--Northamptonshire--History.
Cropping systems--England--Northamptonshire--History.
Northamptonshire (England)--Antiquities.
Shifting cultivation--England--Northamptonshire--History.
Princeton subject headings:
Cropping systems--England--Northamptonshire--History.
Shifting cultivation--England--Northamptonshire--History.