North Carolina SIDS: shapefile sids.shp (based on geometries downloaded
from <a href="http://sal.agecon.uiuc.edu/datasets/sids.zip">http://sal.agecon.uiuc.edu/datasets/sids.zip</a>) and GAL format
neighbour lists ncCC89.gal and ncCR85.gal distributed with <b>spdep</b>,
data from Cressie (1993), neighbour lists from Cressie and Chan (1989)
and Cressie and Read (1985), documented in the nc.sids help page.
