Reference books are used to give you a starting point for your research, providing you with an overview of a topic and an introduction to the specific vocabulary of subject. They will give you the "big picture" and provide you with a starting point for more specific searching.
Encyclopedia of International Relations and Global Politics
REF JZ1160 .E5 2005
Encyclopedia of Public International Law
REF JX1226.E5
Greenwood Encyclopedia of International Relations
REF JZ1160 .N65 2002
International Encyclopedia of Environmental Politics
REF GE170 .I55 2002
International Encyclopedia of Elections
REF JF1001 .I57 2000
International Encyclopedia of Human Rights
REF JC571 .M3243 2000
Oxford Handbook of International Relations
REF JZ1242 .O94 2008
Routledge Encyclopedia of International Political Economy
REF HF1359 .R68 2001