[1]	M. Wegmann and M. Lennert. GRASS User Survey 2004. GRASS Newsletter, 2:2-16, January 2005. ISSN 1614-8746. [ bib | .pdf ]
[2]	#1GRASS Development Team. GRASS 6.0.0beta1 release. GRASS Newsletter, 2:17-18, January. ISSN 1614-8746. [ bib | .pdf ]