Biggeri, A., Catelan, D., Dreassi, E., Rinaldi, L., Musella, V., Veneziano, V. and Cringoli, G. (2007) “Multivariate spatially-structured variability of ovine helminth infections”, Geospatial Health, 2(1), pp. 97–104. doi: 10.4081/gh.2007.258.