Purdue Libraries has many useful constitutional law reference materials. Subject headings to search for books in the Libraries online catalog include:
Many works on constitutional law are government publications located in the HSSE Library. Most recent U.S. Government publications are accessible on the Libraries online catalog. The principal index for locating U.S. Government publications is the Monthly Catalog of U.S. Government Publications (HSSE REF & Periodicals 016.353 UN36). An online version of this from 1994-present is also available.