Li, Jingzhi, author
China Renmin University Press, 2012
eBooks
Russett, Bruce, author
Wadsworth, 2010
Buku Teks
Kinsella, David Todd, author
Wadsworth, Cengage Learning, 2013
Buku Teks
resources for the future, 1981
Buku Teks
Christensen, Kit R., author
McGraw-Hill, 2002
Buku Teks