1. Vortex Interactions
2. D. Moore and P. Saffman,Aircraft Wake Turbulence, edited by J. Olsen, A. Goldberg, and N. Rogers (Plenum, New York, 1971), pp. 339–354.
3. J. Neu, J. Fluid Mech. (to be published).
4. H. Lamb,Hydrodynamics, 6th ed. (Cambridge U.P., Cambridge, 1932), pp. 232–233.