1. T. Pollock, Private communication, 2002.
2. S. Sondhi, M. McClean, B. Dyson, 8th Progress Report on DARPA AIM programme, 2003.
3. A.M. Wusatowska-Sarnek, G. Ghosh, G.B. Olson, M.J. Blackburn, M. Aindow, 2002, in press.
4. M. Aindow, Private communication, 2002.
5. Pratt, Whitney, Private communication, 2003.