@article {Boxer:March 2006:0924-9907:167,
	author = "Boxer, Laurence",
	title = "Homotopy Properties of Sphere-Like Digital Images",
	journal = "Journal of Mathematical Imaging and Vision",
	volume = "24",
	year = "March 2006",
	abstract = "Recent papers have discussed digital versions of the classical fundamental group for digital images. It has been shown that for non-contractible digital simple closed curves, the digital fundamental group is isomorphic to the integers, in analogy with Euclidean simple closed curves. In this paper, we show that the digital fundamental groups of sphere-like digital images <I>S</I><SUB><I>n</I></SUB>, <I>n</I> &#62; 1, are trivial, as are the fundamental groups of their Euclidean analogs <I>S</I><SUP><I>n</I></SUP>.",
	pages = "167-175(9)",
	url = "http://www.ingentaconnect.com/content/klu/jmiv/2006/00000024/00000002/00003619"
	doi = "doi:10.1007/s10851-005-3619-x"
}