@article {1136,
	title = {Resource partitioning in bumblebees: the significance of differences in proboscis length},
	journal = {Oikos},
	volume = {35},
	year = {1980},
	pages = {298-302},
	author = {Ranta, E. and Lundberg, H.}
}
@article {908,
	title = {Habitat and food utilization in subarctic bumblebee community},
	journal = {Oikos},
	volume = {35},
	year = {1980},
	pages = {303-310},
	author = {Lundberg, H. and Ranta, E.}
}
