1. Mitre Geophysics Pty Ltd, PO Box 974, Sandy Bay, Tas. 7006.
2. Pasminco Mining, PO Box 460, Broken Hill, NSW 2880.
3. BHP Research, 245 Wellington Rd, Mulgrave, Vic. 3170.
4. Zonge Engineering, 98 Frederick St, Wetland, SA 5007.
5. Zonge Engineering, 3322 East Fort Lowell Rd, Tucson, Arizona 85716.