@conference {spies1999a,
	title = {Differential range flow estimation},
	booktitle = {Proceedings of the 21th DAGM Symposium on Pattern Recognition},
	year = {1999},
	note = {DAGM award},
	pages = {309--316},
	doi = {10.1007/978-3-642-60243-6_36},
	author = {Hagen Spies and Horst Hau{\ss}ecker and Bernd J{\"a}hne and John L. Barron}
}
