The Sejong Institute, 1994
Buku Teks
Collinwood, Dean W., author
McGraw-Hill, 2001
Buku Teks
Collinwood, Dean W., author
McGraw-Hill, 1999
Buku Teks
Daniel, Hawthorne, author
G.P. Putnam's Sons , 1943
Buku Teks
Oliver, Douglas L., author
Harvard University Press, 1951
Buku Teks