@article {Ruhnau-et-al-05b,
	title = {A variational approach for particle tracking velocimetry},
	journal = {Meas. Science and Techn.},
	volume = {16},
	year = {2005},
	pages = {1449-1458},
	author = {Ruhnau, P. and G{\"u}tter, C. and Putze, T. and Schn{\"o}rr, C.}
}
