Burg, Bob, Mann, John David (2) Petersen, David L. (1) George (1) O'sullivan, David (university of Auckland, Unwin, David (university Of London) (1) Longley, Paul A. (university College London, Goodchild, Michael F. (university Of California At Santa Barbara, Maguire, David J. (environmental Systems Research Institute, Rhind, David W. (city University (1)