edited by Korean National Commission for UNESCO
Hollym, 2003-2004
Buku Referensi
Dick, Archie L.
Unisa Press, 2002
Buku Teks
Osgood, Berrien Cornelius
The Ronald Pres Company, 1951
Buku Teks
Artikel Jurnal
Lanczos, Cornelius
University of Toronto Press, 1966
Buku Teks