1. W.C. Buehler and J.C. Wiley, U.S. Patent No. 3,174,851 March 1965.
2. The substitution of Cu for Ni in NiTi shape memory alloys
3. 12th Aerospace Mechanisms Symposium;Brook,1978
4. Paper 80-C2/PVP-37;Sandberg,1980
5. F.E. Wang and W.J. Buehler, British Patent Specification No. 1,202,404, August 1970.