1. R. A. HELLA and D. S. GNANAMUTHU: Annual Meeting, American Welding Society, St Louis, 10–14 May 1976.
2. D. S. GNANAMUTHU and E. V. LOCKE: US Patent No. 4 015 100, 1976.
3. C. o. BROWN and C. M. BANAS: 52nd Annual Meeting, American Welding Society, San Francisco, 26–29 April 1971.
4. Deep penetration welding with high-power CO2lasers