Cohen, R. J. (2001). Preserving the astronomical sky: Proceedings of the 196th Symposium of the IAU held in United Nations Vienna International Conference Centre in conjunction with UNISPACE III at Vienna, Austria 12 - 16 July 1999. Astronomical Soc. of the Pacific.
Chicago-Zitierstil (17. Ausg.)Cohen, R. J. Preserving the Astronomical Sky: Proceedings of the 196th Symposium of the IAU Held in United Nations Vienna International Conference Centre in Conjunction with UNISPACE III at Vienna, Austria 12 - 16 July 1999. Provo, Utah: Astronomical Soc. of the Pacific, 2001.
MLA-Zitierstil (9. Ausg.)Cohen, R. J. Preserving the Astronomical Sky: Proceedings of the 196th Symposium of the IAU Held in United Nations Vienna International Conference Centre in Conjunction with UNISPACE III at Vienna, Austria 12 - 16 July 1999. Astronomical Soc. of the Pacific, 2001.