1. Sumber Hukum Internasional
Heru Susetyo, SH. LL.M. M.Si.
Rebbeca M. Wallace, International Law (Sweet and Maxwell, 1997)

2. Pasal 38 Statute of International Court of Justice
Sumber hukum internasional :
International conventions
International customary law
General principles of law
Judicial decisions and teaching of the most highly qualified publicist of the various nations

3. International Customary Law
Custom = is a practice followed by those concerned because they feel legally obliged to behave in such a way.
A rule of customary international law derives its law hallmark through the possesion of two elements : 1. material and 2. psychological element
Opinio juris and state practice; both are complementary in the creation of customary international law.

4. Material & psychological element
Material >Refers to he behavior and practice of states (state practice)
Psychological > subjective conviction held by states that the behaviour in question is compulsory and not discretionary.

5. Sumber Hukum yang Lain Acts of international organization
Regional organization
The International Law Commission
Jus cogens

6. Jus Cogens
Technical term given to those norms of general international law which are of a peremptory force and from which, as a consequence, no derogation may be made, except by another norm of equal weight.
Peremptory norm of general international law is accepted and recognized by the international community of States as whole.
Jus cogens is the label for what are essentially the public policy rules of international legal system.

7. Contoh Jus Cogens The prohibition of genocide and torture
The realisation of the principle of self determination