1. Arpigny, C. 1994, in AIP Conf. Proc. 312, Molecules and Grains in Space, ed. I. Nenner (New York: AIP), 205
2. Barden, S. C., Armandroff, T., Massey, P., Groves, L., Rudeen, A. C., Vaughnn, D. & Muller, G. 1993, in ASP Conf. Proc. 37, Fiber Optics in Astronomy II, ed. P. M. Gray (San Francisco: ASP), 185
3. Evolution of the Outgassing of Comet Hale-Bopp (C/1995 O1) from Radio Observations