1. Altschul, S. F., Madden, T. L., Schäffer, A. A., Zhang, J., Zhang, Z., Miller, W., et al. (1997). Gapped BLAST and PSI-BLAST: a new generation of protein database search programs. Nucleic Acids Research, 25, 3389–3402.
2. Corpet, F. (1988). Multiple sequence alignment with hierarchical clustering. Nucleic Acids Research, 16, 10881–10890.
3. Costantini, M., Luigi, M., Luison, D., Mangiaracina, P., Albanese, G., Tomassoli, L., et al. (2011). Diagnosis, characterization and distribution of pospiviroids in ornamental plants in Italy. Journal of Plant Pathology, 93, S4.14.
4. Di Serio, F. (2007). Identification and characterization of Potato spindle tuber viroid infecting Solanum jasminodes and S. rantonnetii in Italy. Journal of Plant Pathology, 89, 297–300.
5. Ding, B., & Itaya, A. (2007). Viroid: A useful model for studying the basic principles of infection and RNA biology. Molecular Plant-Microbe Interactions, 20, 7–20.