Time delay and lens redshift for the doubly imaged BAL quasar SBS 1520+530 I. Burud, J. Hjorth, F. Courbin, J. G. Cohen, P. Magain, A. O. Jaunsen, A. A. Kaas, C. Faure and G. Letawe A&A, 391 2 (2002) 481-486 Published online: 02 August 2002 DOI: 10.1051/0004-6361:20020856