1. Malik, F. and Khan, E. and Quireshi, I. and (2002) Radiat. Meas., 35, pp. 301.
2. Kratschmer, W. and Getner, W.(1976). . Proceedings of the Lunar Science Conference 7th Pergamon . In [ pp. 501] . .
3. Henke, R. and Benton, E.(1973). . 13th International Conference Cosmic Rays . In [ pp. 3261] . .
4. Mark, T. and Walder, G. (1988) Mat. Proc. Res. Soc. Symp., 112, pp. 693.
5. Sandhu, A. and Westgate, J. and Alloway, B. (1993) Nucl. Tracks Radiat. Meas., 21, pp. 479.