Frederick S. Merritt and Jonathan T. Ricketts, editor
McGraw-Hill, Inc, 1994
Buku Referensi
David Linden, editor in chief
McGraw-Hill, 1995
Buku Referensi
Korean Overseas Information Service, 1993
Buku Referensi
Sprague, Jo, author
Wadsworth/Cengage Learning, 2013
Buku Teks
Kim, Se-Kwon, author
Wiely-Blackwell, 2012
Buku Teks