From the researcher’s perspective, the legal system of the VCS is best approached by examining the documents that established the nation and formed the constitutional basis for the world’s smallest nation state. The most useful work for this purpose is Amos Peaslee, Constitutions of Nations, which provides a short summary of the nation’s legal composition, the text of the Lateran Treaty, extracts from the accompanying 1929 Concordat, the complete text of the six Fundamental Laws of 1929, and a short bibliography.
The “Vatican City” section by Philip Raworth in Blaustein and Blaustein (eds.), Constitutions of Dependencies and Territories, should be consulted for the 2001 Fundamental Law and the 1984 Concordat between the Holy See and the Italian Republic. It should be noted that since this is treated as a “territory” by Blaustein and Blaustein there is no entry for the VCS or the Holy See in Blaustein and Flanz (eds.), Constitutions of the Countries of the World.
HeinOnline provides digital access to a number of the VCS fundamental laws in their World Constitutions Illustrated library. In addition, that collection also includes commentaries, scholarly articles and bibliographies that might be of interest to those researching the jurisdiction.