1. Registration Record of Aluminum Association Alloy Designations and Chemical Composition Limits for Wrought Aluminum Alloys, The Aluminum Association.
2. Aluminum Standards and Data, 2nd ed. The Aluminum Association (December 1969).
3. Alcoa Aluminum Handbook, Aluminum Company of America (1967).
4. P. J. Wright (Alcoa), private communication.
5. R. A. Schultz, Alcoa Aluminum Alloy 2021, Alcoa Green Letter, Aluminum Company of America (April 1968) (not released for publication).