Hydrodynamic interactions between widely separated particles at a free surface B. Cichocki, M. L. Ekiel-Jeżewska, G. Nägele and E. Wajnryb Europhys. Lett., 67 3 (2004) 383-389 Published online: 01 July 2004 DOI: 10.1209/epl/i2004-10077-9