A video film: Vortex shedding and acoustic resonances induced in flow ducts containing plates: 1979, M. C. Welsh, S. A. T. Stoneman and R. Parker. Running time 27 minutes. Copies available from Mr S. A. T. Stoneman or Dr R. Parker, University College of Swansea, Swansea, SA2 8PP, United Kingdom. Prices: U.K. (625 lines 50 frames/second) on UMATIC or V.H.S. cassettes £30, copying to customer's cassette £10; U.S.A. formats £75; plus postage if outside U.K.; prices subject to adjustment for cassette price changes