Columbia subject headings:
Harvard subject headings:
Ecology--Philosophy
Ham, Sŏk-hŏn, 1901-1989--Ecology.
Ham, Sŏk-hŏn, 1901-1989--Philosophy.
Ham, Sŏk-hŏn, 1901-1989--Religion.
Princeton subject headings:
Ham, Sŏk-hŏn, 1901-1989--Religion.
Ham, Sŏk-hŏn, 1901-1989.