@article {,
	title = {Further analysis of Near Eastern obsidians},
	journal = {Proceedings of the Prehistoric Society},
	volume = {34},
	year = {1968},
	note = {first use of fall off curves and regression analysis in sourcing.},
	pages = {319-331},
	keywords = {regression analysis exchange trade falloff},
	author = {Renfrew, Colin and J. E. Dixon and J. R. Cann}
}