Columbia subject headings:
Harvard subject headings:
Agreculturists--Korea--Biography.
Farm management--Korea--History.
Philosophy, Korean.
Sirhak school.
U, Ha-yŏng, 1741-1812.
Princeton subject headings:
Agriculturists--Korea--Biography.
Farm management--Korea--History.
Philosophy, Korean.
Sirhak school.
U, Ha-yŏng, 1741-1812.