Columbia subject headings:
Astronomical clocks--Korea--History.
Astronomical instruments--Korea--History.
Astronomical observatories--Korea--History.
Astronomy--Korea--History.
Korea--Civilization--1392-1910.
Science and state--Korea--History.
Harvard subject headings:
Astronomical clocks--Korea--History.
Astronomical instruments--Korea--History.
Astronomical observatories--Korea--History.
Astronomy--Korea--History.
Korea--Civilization--1392-1910
Science and state--Korea--History.
Princeton subject headings:
Astronomical instruments--Korea--History.
Astronomy, Korean--History.
Korea--Civilization--1392-1910.