1. V.G. Welsby, “Electronic scanning of focussed arrays”, J. Sound Vib., 8:390 (1968).
2. Also, V.G. Welsby, D.J. Creasey and N.J. Barnickle, “Narrow beam focussed array for electronically scanned sonar: some experimental results”, J. Sound Vib., 30: 237 (1973).
3. L.J. Cutrona, “Comparison of sonar system performance achievable using synthetic-aperture techniques with the performance achievable by more conventional means”, J. Acoust. Soc. Amer., 58: 336 (1975).
4. Z. Reut, N.G. Pace and M.J.P. Heaton, “Computer classification of seabeds by sonar”, Nature, 314:426 (1985).
5. Also, by the same authors, “Statistical properties of sidescan sonar signals and the computer classification of sea-beds”, Proc. Inst. Acoustics, 7 (Pt.3): 102 (1985).