@article {1282,
	title = {Western Diptera: Descriptions of new genera and species of Diptera from the region west of the Mississippi and especially from California},
	journal = {Bulletin of the United States Geological and Geographical Survey of the Territories},
	volume = {3},
	year = {1877},
	pages = {189-354},
	url = {http://www.biodiversitylibrary.org/item/98702},
	author = {Osten Sacken, C. R.}
}
@article {2922,
	title = {Review of the American xylotine syrphid-flies},
	journal = {Proceedings of the United States National Museum},
	volume = {69},
	year = {1926},
	pages = {1-52},
	url = {http://si-pddr.si.edu/dspace/bitstream/10088/15651/1/USNMP-69_2635_1926.pdf},
	author = {Shannon, R.C.}
}
@article {251,
	title = {Classification of Xylotini (Diptera, Syrphidae)},
	journal = {Acta Zoologica Fennica},
	volume = {156},
	year = {1978},
	pages = {1-153},
	keywords = {Arthropods},
	author = {Hippa, H.}
}
