@book{38120,
	author = {Dorian, Nancy C.},
	title = {Investigating variation},
	publisher = {Oxford University Press,},
	year = {2009.},
	series = {Oxford studies in sociolinguistics},
	address = {New York ;},
	url = {http://dx.doi.org/10.1093/acprof:oso/9780195385939.001.0001}
}