This guide is the product of years of teaching experience in methodology of law. It focuses on how to find and use instruments of international organizations and is mainly intended to be a practical instrument for students at an advanced level, as well as for lawyers and public servants. In a practical way, the book offers a detailed description on how to do research in sources of international law in the most efficient way. It examines different sources of international law and provides answers to a variety of questions one may be confronted with when dealing with international law. What are these sources? Where can they be found? Once they are found, how can these sources be read and interpreted? The main focus lies on the wide range of electronic databases on international law, although reference is also made to the traditional means of finding sources. The use of screenshots and clear examples make this book a very practical instrument and an extremely useful tool.