V. Schwieger. Proceedings on International Symposium Modern Information and GPS Technology - Aspects and Implications of their Application, Sofia, Bulgarien, (1999)
O. Heunecke, K. Nerkamp, H. Pelzer, and V. Schwieger. Proceedings on International Symposium Modern Information and GPS Technology - Aspects and Implications of their Application, Sofia, Bulgarien, (1999)