Lee, byeong-Uk, author
Ecolivre, 2009
Buku Teks
Yearn, Hong-choi, author
Shinkwang Publishing, 2008
Buku Teks
Jeong, Gu Hyeon., author
Wisdom House, 2008
Buku Teks
Barrow, Christopher J., author
Routledge, 2006
Buku Teks
editor, Gunter Schramm and Jeremy J. Warford
The World Bank, 1991
Buku Teks