@article {35937,
	title = {Epilithic algal nitrogen fixation, standing crops and productivity in five rivers flowing through the oil sands region of Alberta/Canada},
	volume = {79},
	year = {1988},
	pages = {109-143},
	publisher = {Archiv f?r Hydrobiologie Supp.},
	author = {Charlton, S. E. D. and Hickman, M.}
}
