Columbia subject headings:
Harvard subject headings:
Astronomical clocks
Astronomical instruments
Astronomical instruments--History.
Astronomy--Korea--History.
Clocks and watches--Korea--History.
Kwansanggam (Korea)
Scientific apparatus and instruments--Korea--History.
Sŏunʼgwan (Korea)
Princeton subject headings:
Astronomical clocks--Korea--Sŏunʾgwan--History.
Astronomical instruments--Korea--Sŏunʾgwan--History.