RYERSON, Robert A. - BATTERHAM, Robert J. An Approach to the Development of a Sustainable National Geomatics Infrastructure. In Photogrammetric engineering * remote sensing : journal of the American Society for photogrammetry and remote sensing. - American Society for Photogrammetry and Remote Sensing : Bethesda. ISSN 0099-1112, 2000, vol. 66, no. 1, s. 17-28.