This study analyzed citations in four journals, "Annals of the Association of American Geographers," "Cartography and Geographic Information Science," "International Journal of Geographical Information Science," and "Cartographic Journal," using Bradford's Law of Scattering to identify three influence zones indicating core and peripheral titles in the study areas of GIS. Journals were ranked resulting in twenty-three core journals and 187 secondary journals. Scores for relevant indexing/abstracting services are also given to describe access points and coverage. The results can assist librarians and collection managers to support research in their institutions where GIS is both used and studied.