(2010) “First record of Citrus viroid II (CVd-II) associated with gummy bark disease in sweet orange (Citrus sinensis) in Egypt”, New Disease Reports21, p. 24. doi:10.5197/j.2044-0588.2010.021.024.
(2004) “Citrus viroid II variants associated with 'Gummy Bark' disease”, European Journal of Plant Pathology110 (10), p. 1047–1052. doi:10.1007/s10658-004-0815-2. 27567491.