Wegener, Frank C.
Greeswood Press , 1957
Buku Teks
Winch, Christopher, author
Routledge, 2008
Buku Teks
editor Philip Cam
Korean National Commission for UNESCO, 2003
Buku Teks
Park, Joe
Macmillan, [date of publication not identified]
Buku Teks
Munk, Arthur W.
Abingdon Press, 1965
Buku Teks