1. For example, see Y. C. JEAN, in: Positron Spectroscopy of Solids, A. DUPASQUIER and A. P. MILLS, Jr. (Eds), IOS Press, Amsterdam, 1995, p. 563.
2. For example, see R. N. WEST, in: Positron Spectroscopy of Solids, A. DUPASQUIER and A. P. MILLS, Jr. (Eds), IOS Press, Amsterdam, 1995, p. 75.
3. Y. C. JEAN, H. NAKANISHI, L. Y. HAO, T.C. SANDRECZKI, Phys. Rev., B42 (1990) 9705.
4. Y. C. JEAN, Y. RHEE, Y. LOU, H. L. YEN, H. CAO, K. CHEONG, Y. GU, Phys. Rev., B (in press).
5. S. BERKO, Momentum Distributions, R. N. SILVER, P. E. SOKOL (Eds), Plenum Press, New York, 1989, p. 273.