@book {deFries2003Alterra,
	title = {{De Bodemkaart van Nederland digitaal}},
	year = {2003},
	pages = {45},
	publisher = {Alterra},
	organization = {Alterra},
	address = {Wageningen},
	author = {de Fries, F. and Groot, W.J.M. and Hoogland, T. and Denneboom, J.}
}