Columbia subject headings:
Agriculture--Early works to 1800.
Agriculture--Economic aspects.
Agriculture--Germany--Early works to 1800.
Grain--Growth.
Growth (Plants)
Harvard subject headings:
Agriculture--Early works to 1800
Agriculture--Economic aspects
Agriculture--Germany--Early works to 1800.
Grain--Growth.
Growth (Plants)
Princeton subject headings:
Agriculture--Early works to 1800.
Agriculture--Economic aspects.
Agriculture--Germany--Early works to 1800.
Grain--Growth.
Growth (Plants)