@book {Nielsen2003Catena,
	title = {Spatial and Temporal Statistics {\textendash}- Sampling Field Soils and Their Vegetation},
	year = {2003},
	pages = {614},
	publisher = {Catena-Verlag},
	organization = {Catena-Verlag},
	address = {Reiskirchen},
	author = {Nielsen, D. and Wendroth, O.}
}