Salem, N., Mansour, A., Al-musa, A. and Al-nsour, A. (2003) “Seasonal variation of Prunus necrotic ringspot virus concentration in almond, peach, and plum cultivars”, Phytopathologia Mediterranea, 42(2), pp. 155–160. doi: 10.14601/Phytopathol_Mediterr-1708.