7 Paul A, Sigru R M, Dauwe C, Dorikens-Vanpraet L, Dorikens M. J Phys C: Solid State Phys, 1974; 7: 2180
[8]
8 Singh Y P, West R N, Paul A. J Phys C: Solid State Phys, 1976; 9: 305
[9]
9 Yavari A R, Lejay P. J Cryst Growth, 1988; 91: 290
[10]
10 Usmar S G, Rawson H, West R N. In: Coleman P G, Sharma S C, Diana L M eds., Positron Annihilation, Proc 6th Int Conf, The University of Texas at Arlington, April 3--7, 1982, Amsterdam: North-Holland, 1983: 660
[11]
11 Shiotani N. In: Coleman P G, Sharma S C, Diana L M eds., Positron Annihilation, Proc 6th Int Conf, The University of Texas at Arlington, April 3--7, 1982, Amsterdam: North-Holland, 1983: 561
[12]
12 Morse P, Corbel C. In: Brandt W, Dupasquier A eds., Positron Solid-State Physics, Amsterdam: North-Holland, 1983: 679
