Positron annihilation : Proceedings of the 9th International Conference on Positron Annihilation, August 26-31, 1991, Szombathely, Hungary. Pt.2 pp.921-924, 1992. Aederlmannsdorf, Switzerland. Trans Tech Publications
Positron annihilation : Proceedings of the 9th International Conference on Positron Annihilation, August 26-31, 1991, Szombathely, Hungary. Pt.2 pp.1129-1132, 1992. Aederlmannsdorf, Switzerland. Trans Tech Publications