@article {keitt-etal-2001,
	title = {Allee Effects, Invasion Pinning, and Species{\textquoteright} Borders},
	journal = {The American Naturalist},
	volume = {157},
	year = {2001},
	pages = {203{\textendash}216},
	author = {Keitt, TH and Lewis, M A and Holt, R D}
}
