Papastefanou, C; Manolopoulou, M; Stoulos, S; Ioannidou, A; Gerasopoulos, E (2001). "Coloured rain dust from Sahara Desert is still radioactive". Journal of Environmental Radioactivity. 55 (1): 109–112. doi:10.1016/S0265-931X(00)00182-X. PMID11381550.
Papastefanou, C; Manolopoulou, M; Stoulos, S; Ioannidou, A; Gerasopoulos, E (2001). "Coloured rain dust from Sahara Desert is still radioactive". Journal of Environmental Radioactivity. 55 (1): 109–112. doi:10.1016/S0265-931X(00)00182-X. PMID11381550.