@article {38124,
	title = {Tectonic controls on regional coalification and vitrinite anisotropy of Lower Cretaceous coals in the Alberta Foothills, Canada},
	volume = {162},
	year = {1991},
	pages = {375-383},
	publisher = {Bulletin de la Societe Geologique de France},
	author = {Langenberg, W. and Kalkreuth, W.}
}
