Oh, Song-chan, 1940-
Min Eum Sa, 1992
Buku Referensi
Jeju Tourism Organization, 2011
Buku Teks SO
Chapman, Sandra C.
Taylor & Francis, 2000
Buku Teks SO
Hughes, Michael
McGraw-Hill, Higher Education, 2009
Buku Teks SO
Zanden, James W. Vander
McGraww-Hill, 1996
Buku Teks SO