1. 1) For example, D. K. Kim and K. Okazaki: P/M in Aerospace and Defense Technology, MPIF, Princeton, NJ., (1991), p. 365.
2. 2) D. K. Kim and K. Okazaki: to be published, in Proc. of ISMA ’91, held at Kyoto, (1991).
3. 3) F. R. Frasier, D. R. Backer and M. J. Kaufman: High Temperature Niobium Alloys, TMS, Cleveland, Ohio, (1991), p. 121.
4. 4) R. Ayer and R. Ray: Met. Trans, 22A (1991), 1901.
5. 5) K. Isonishi and K. Okazaki: submitted for publ. to J. Mater. Sci., (1992).