HST and ground-based observations of the gravitational lens system Q1009-0252 A & B J.-F. Claeskens, S. V. Khmil, Dong Wook Lee, D. Sluse and J. Surdej A&A, 367 3 (2001) 748-758 Published online: 15 March 2001 DOI: 10.1051/0004-6361:20000491