Korean Overseas Information Service
Hollym, 2003
Buku Teks
Son Yeong-hak, author
Seoul : Dahal Media, 2009
Buku Teks
translated by Noh Jeo-yong
Yeungnam University Press, 2006
Buku Teks
Lee, Haiyoung, author
Hollym, 2006
Buku Teks
Trewartha, Glenn T., author
McGraw-Hill, 1967
Buku Teks