@article {Mitasova2005IEEE,
	title = {{Simultaneous Spline Approximation and Topographic Analysis for Lidar Elevation Data in Open-Source GIS}},
	journal = {IEEE Geoscience and Remote Sensing Letters},
	volume = {2},
	year = {2005},
	pages = {375-379},
	author = {Mitasova, H. and Mitas, L. and Harmon, R.}
}