@article {MillerTengVavaThur1,
	title = {Separators for sphere-packings and nearest neighbor graphs},
	journal = {J. ACM},
	volume = {44},
	year = {1997},
	pages = {1-29},
	author = {G. L. Miller and S.-H. Teng and W. Thurston and S. A. Vavasis}
}