International Symposium Management of Geodetic Data Copenhagen, Geodætisk institut (Denmark), & Tscherning, C. (1981). Proceedings of the International Symposium Management of Geodetic Data København 24.-26. August 1981. Produced for the Geodetic Institute by Akademisk vorlag.
توثيق أسلوب شيكاغو (الطبعة السابعة عشر)International Symposium Management of Geodetic Data Copenhagen, Geodætisk institut (Denmark), و Carl Tscherning. Proceedings of the International Symposium Management of Geodetic Data København 24.-26. August 1981. København, Danmark: Produced for the Geodetic Institute by Akademisk vorlag, 1981.
توثيق جمعية اللغة المعاصرة MLA (الطبعة الثامنة)International Symposium Management of Geodetic Data Copenhagen, et al. Proceedings of the International Symposium Management of Geodetic Data København 24.-26. August 1981. Produced for the Geodetic Institute by Akademisk vorlag, 1981.