@article {Pardo2005CG,
	title = {Multiple indicator cokriging with application to optimal sampling for environmental monitoring},
	journal = {Computers \& Geosciences},
	volume = {31},
	number = {1},
	year = {2005},
	pages = {1-13},
	author = {Pardo-Iguzquiza, Eulogio and Dowd, Peter A.}
}