@article {31315,
	title = {Coal inclusions of the Athabasca tar sands: characterization and direct determination of vanadyl porphyrin content by electron spin resonance},
	volume = {42},
	year = {1978},
	pages = {359-365},
	publisher = {Geochimica et Cosmochimica Acta},
	author = {Hocking, Martin B. and Premovic, Pavle I.}
}
