@article{BaNiSc94,
	author = {Douglas Bauer and Thomas Niessen and Edward Schmeichel},
	title = "Neighborhood unions, degree sums, toughness and 2-factors",
	pages = "47-57",
	journal = "Congress. Numer.",
	volume = "100",
	year = 1994,
	hsb = {RWTH-CONV-223139},
	}