Jeremy L. Mennis Donna Peuquet Liujian Qian A conceptual framework for incorporating cognitive principles into geographical database representation. 501-520 2000 14 International Journal of Geographical Information Science 6 http://taylorandfrancis.metapress.com/openurl.asp?genre=article&issn=1365-8816&volume=14&issue=6&spage=501 db/journals/gis/gis14.html#MennisPQ00