1. Seminara, G. & Hall, P. 1976 Proc. R. Soc. Lond. A 350,299.
2. Davidson, B. J. & Riley, N. 1972 J. Fluid Mech. 53,287.
3. Schlichting, H. 1932 Phys. Z. 33,327.
4. Hall, P. 1982 J. Fluid Mech. 124,475.
5. Duck, P. W. & Hall, P. 1981 Z. angew. Math. Phys. 32,102.