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21. "Selection and Weldability of Non-Heat- Treatable Aluminum Alloys," ASM Handbook, Vol. 6: Welding. Brazing. and Soldering, C. Cross & M. Kohn, ASM International, 1993, pp. 537-540.
http://eagar.mit.edu/3.37/H-3371-21.pdfRespectfully,
Henry