Dynamical effects of comet P/Halley gas production K. Szegö, J. F. Crifo, L. Földy, J. S. V. Lagerros and A. V. Rodionov A&A, 370 2 (2001) L35-L38 Published online: 15 May 2001 DOI: 10.1051/0004-6361:20010331