@article {1140,
	title = {Why are there so many species? Spatio-temporal heterogeneity and northern bumblebee communities},
	journal = {Oikos},
	volume = {36},
	year = {1981},
	pages = {28-34},
	author = {Ranta, E. and Veps{\"a}l{\"a}inen, K.}
}
