HeinOnline: Foreign & International Law Resources Database (FILRD) - includes international law yearbooks and periodicals, digests of U.S. practice in international law (Wharton, Moore, Hackworth, Whiteman), Permanent Court of International Justice (PCIJ) decisions, and Moore's History and Digest of the International Arbitrations to which the United States Has Been a Party.
LexisNexis for Law Students - includes U.S. treaties; International Legal Materials (ILM); EU law treatises, ECJ cases, EU treaties, regulations, directives; ICJ decisions; ECHR judgments and decisions; international arbitration and internaitonal trade materials; Martindale-Hubbell International Law Digests, including Hague Conventions; non-English news.
Max Planck Encyclopedia of Public International Law Online (MPEPIL/EPIL).
Parry & Grant Encyclopaedic Dictionary of International Law (3d ed, 2009; eBook).
Recueil des cours = Collected Courses (Hague Academy of International Law) - the Hague Academy Collected Courses Online (Martinus Nijhoff) - books, book chapters, mini-monographs on public international law topics.
Westlaw - includes U.S. treaties, International Legal Materials (ILM), international commercial arbitration databases, investor-state materials, ICJ, ICTR, ICTY, Iran-U.S. Claims Tribunal, WTO, GATT decisions; European Union legislation, treaties, cases, journals (European Competition Law Review, Common Market Law Reports); International Organization (INOG), Foreign Affairs (FORGNAFF), Foreign Policy (FORGNPLY), Global Governance (GLBLGOVERN). Westlaw also has the Legal Journals Index (LJI), WORLD-JLR, and International Law Texts & Periodicals (INT-TP).
WestlawNext ---> All Content ---> International Materials (Australia, Canada, UK, EU, and including law journals).
World Legal Information Institute (WorldLII). Includes international legal decisions and treaties databases.