@article{24939, author = "Gendt, G. and Montag, H. and Zentralinstitut für Physik der Erde and XXIII. Plenary Meeting of COSPAR Technical Panel on Dynamics of Artificial Satellites and Space Probes, Budapest, June 1980", title = "The Program Systems "Potsdam-4" for Differential Improvement of Orbital Elements and Other Parameters. XXIII.Plenary Meeting of COSPAR Technical Panel on Dynamics of Artificial Satellites and Space Probes, Budapest, June 1980 ", year = "1980", note = "1 sv., 14 liter.", }