@incollection {geissler1999a,
	title = {Depth-from-focus for the measurement of size distributions of small particles},
	volume = {3: Systems and Applications},
	year = {1999},
	pages = {623-646},
	publisher = {Academic Press},
	chapter = {29},
	author = {Peter Gei{\ss}ler and Thomas Scholz and Bernd J{\"a}hne and Horst Hau{\ss}ecker and Peter Gei{\ss}ler}
}
