M. H.-E.-. WAFA, R. M. AWADALLAH, A. E. MOHAMMED, and M. N. RASHED, “?DETERMINATION OF TRACE ELEMENTS IN BARLEY, BEET AND PURSLANE OF KALABSHA AREA OF ASWAN IN EGYPT”, Pakistan Journal of Scientific & Industrial Research, vol. 38, no. 11-12, pp. 410–413, Dec. 1995.