@article {36045,
	title = {Nitrogen compounds in Athabasca asphaltene : the vanadyl porphyrins},
	volume = {4},
	year = {1988},
	pages = {171-179},
	publisher = {AOSTRA Journal of Research},
	author = {Frakman, Z. and Ignasiak, T. M. and Montgomery, D. S. and Strausz, O. P.}
}
