How to Find and Use Sources

Good research has three parts: the right source, the right weight, and the right pinpoint (the exact paragraph or page). Judges do not count your sources. They test them.

Step 1: Learn the background first

Before you search for cases, read one good textbook chapter on the topic. This gives you the map. Without a map, you will not know which sources matter.

Field	Good starting books (use whichever your library has)
Public international law (Jessup)	Shaw, International Law; Crawford, Brownlie’s Principles of Public International Law; Dixon, Textbook on International Law
IHL (Henry Dunant)	Sassòli, International Humanitarian Law; Solis, The Law of Armed Conflict; ICRC Commentaries
Environmental law (Stetson)	Sands, Principles of International Environmental Law; Birnie, Boyle and Redgwell
Arbitration and CISG (Vis)	Redfern and Hunter on International Arbitration; Schlechtriem and Schwenzer, Commentary on the CISG

A textbook is for learning. Do not use it as your main authority in the memorial unless a treaty, case or official text says the same thing.

Step 2: Know the ladder of authority

Judges ask: “How strong is your source?” Use this ladder.

Level	What it is	Examples
Strongest	Treaties binding on the parties; clear customary law	Geneva Conventions; UN Charter; the Vienna Convention on the Law of Treaties (VCLT) rules that reflect custom
Very strong	Decisions of the main court on the point	ICJ judgments and advisory opinions; in Vis, decisions on the CISG from national courts and tribunals
Strong	Official codification and other tribunals	ILC Articles on State Responsibility (2001) with commentary; ITLOS, ICC, ICTY, ICTR, arbitral awards
Helpful	Respected scholars and expert bodies	ICRC Customary IHL Study; CISG Advisory Council Opinions; leading journal articles
Weak	Soft law, resolutions, press reports, blogs	UN General Assembly resolutions (unless they show custom); news; blog posts

For ICJ-style moots, Article 38(1) of the ICJ Statute is your checklist: treaties, custom, general principles, then judicial decisions and scholars as subsidiary means.

Formula for weight: Is it Binding? Is it Relevant? Is it Recent? Is it Authoritative? If a source fails any two of these four, find a better one.

Step 3: Where to look (many are free)

Many undergrad students cannot access paid databases. You do not need them to do excellent research. Start here:

• ICJ website. Judgments, advisory opinions, pleadings and separate opinions, free.
• UN Treaty Collection. Treaty texts and status (who is a party).
• UN International Law Commission (ILC) website. Draft articles and commentaries.
• ICRC IHL Databases. Treaties, commentaries and the customary law study.
• ITLOS, PCA and ICC websites. Decisions, awards and legal texts.
• UNCITRAL and CISG databases (for example, the Pace Law CISG Database and CISG-online). Free case law and commentary on the CISG.
• Italaw and UNCTAD Investment Policy Hub. Investment arbitration awards and treaties.
• Google Scholar, SSRN and open-access journals. The European Journal of International Law and others have free articles. EJIL:Talk!, Opinio Juris, Just Security, DraftLaw Research and Völkerrechtsblog are useful for current debates, but treat them as weak sources.
• Your university library. Ask your librarian and your coach about JSTOR, HeinOnline, Westlaw, LexisNexis and Oxford Public International Law. Many universities have them and students never ask.
• The snowball trick. Take one good case or article. Read its footnotes. Find the three most useful sources there. Read their footnotes. Within an hour you have a reading list.

Step 4: How to read a case fast and well

• Read the summary or first paragraphs to learn the question and the result.
• Find the reasoning paragraphs (often called “the Court’s reasoning” or “considerations”).
• Note the paragraph numbers. You will need them.
• Separate the ratio (the reasoning needed for the decision) from obiter (side comments). Judges care.
• Read separate and dissenting opinions. They tell you the other side’s best argument.
• Check what later cases said about it. Has it been followed, limited or ignored?
• Never cite a headnote or a summary website as if it were the judgment. Cite the judgment.

Step 5: Keep a source log from day one

An example log:

Source	Pinpoint	What it proves (one sentence)	Strength	Issue	Short quote (under 25 words)
Gabčíkovo-Nagymaros (ICJ 1997)	para 140	Sustainable development must guide use of shared rivers	Level 2	Issue 2	“…”
ILC Articles on State Responsibility, Art 2	Art 2	Elements of an internationally wrongful act	Level 3	Issue 2	“…”

This log saves weeks. It also helps you find a quote in seconds when a judge asks.

Important tips and tricks

Rules for honest and safe research

• Open every source you cite. Never cite a case you only saw named in a blog.
• Do not trust AI tools for citations. Chatbots can invent cases, paragraph numbers and quotes that look real. Use them to understand a topic if you like but check every source yourself on the official site.
• Always give a pinpoint. A citation without a paragraph or page number looks lazy.
• Check the rules. Some moots restrict sources, set a cut-off date, or limit how many you can cite.
• Quote small. Use short quotes only where the exact words matter. Put the rest in your own words.
• Find the other side’s sources too. You will have to argue against them.

Quick quality check for each source

• Is it a primary source (the actual treaty or judgment) rather than somebody’s summary?
• Does it really say what I claim? Reread the paragraph.
• Is it binding on this court, or only persuasive?
• Could the other side say it is about a different situation? How will I answer that?