Speckle observations of binary systems measured by Hipparcos J.-L. Prieur, E. Oblak, P. Lampens, M. Kurpinska-Winiarska, E. Aristidi, L. Koechlin and G. Ruymaekers A&A, 367 3 (2001) 865-875 Published online: 15 March 2001 DOI: 10.1051/0004-6361:20000550