Castrignanò, A., D. De Benedetto, G. Girone, F. Guastaferro, and D. Sollitto. “Characterization, Delineation and Visualization of Agro- Ecozones Using Multivariate Geographical Clustering”. Italian Journal of Agronomy, vol. 5, no. 2, June 2010, pp. 121-32, doi:10.4081/ija.2010.121.