@article {caselton1984optimal,
	title = {Optimal monitoring network designs},
	journal = {Statistics and Probability Letters},
	volume = {2},
	number = {4},
	year = {1984},
	pages = {223{\textendash}227},
	publisher = {Elsevier},
	author = {Caselton, William F and Zidek, James V}
}
