Patents
1. D.R.S. Cumming, R.J. Blaikie, T.D. Drysdale, Filter, GB 0126737.6., PCT/GB2002/005037, 7 Nov. 2001. 2. D.R.S. Cumming, T. D. Drysdale, Security tag, GB 0305606.6, 12 March 2003.
2. D.R.S. Cumming, T. D. Drysdale, Security tag, GB 0305606.6, 12 March 2003.