@article {32205,
	title = {Significance of the variogram with some examples from the Athabasca tar sands},
	volume = {18},
	year = {1979},
	pages = {41-46},
	publisher = {Journal of Canadian Petroleum Technology},
	url = {http://www3.interscience.wiley.com/cgi-bin/fulltext/118735109/PDFSTART},
	author = {Zwicky, R. W.}
}
