Russett, Bruce, author
Wadsworth, 2010
Buku Teks
Kinsella, David Todd, author
Wadsworth, Cengage Learning, 2013
Buku Teks
Russett, Bruce
WH Freeman, 1985
Buku Teks
Christensen, Kit R., author
McGraw-Hill, 2002
Buku Teks
Li, Jingzhi, author
China Renmin University Press, 2012
eBooks