@article{Ni98,
	author = {Thomas Niessen},
	title = "A characterization of graphs having all (g,f)-factors",
	pages = "152--156",
	journal = "Journal of Combinatorial Theory, Series B",
	volume = "72",
	number = "1",
	doi = "10.1006/jctb.1997.1797",
	year = 1998,
	hsb = {RWTH-CONV-223160},
	}