1. Engelis Th., Radial Orbit Error Reduction and Sea Surface Topography Determination Using Satellite Altimetry; Report No.377; Ohio State University; Columbus, Ohio; 1987
2. Gredel J., Reigber C., The German Processing and Archiving Facility for ERS-1; Geo Information Systeme; 2; 1991
3. Rapp R., The Treatment of Permanent Tidal Effects in the Analysis of Satellite Altimeter Data for Sea Surface Topography; Manuscripta Geodaetica; 14, 368–372; 1989
4. Rapp R.H., Wang Y.M., Pavlis N., 1991
Degree 360 Model Development; paper presented at EGS General Assembly; Wiesbaden; 1991
5. Schwintzer P., Reigber Ch., Barth W., Massmann F.H., Raimondo J.C., Gerstl M., Bode A., Li H., GRIM4 Earth gravity field models in support of ERS-1 and SPOT- 2; paper presented at XX IUGG General Assembly,; Vienna, Austria; 1991