@article {EastmanFulk1993PERS,
	title = {{Long sequence time series evaluation using standardized principal components}},
	journal = {Photogrammetric Engineering \& Remote Sensing},
	volume = {59},
	number = {6},
	year = {1993},
	pages = {991-996},
	author = {Eastman, J.R. and Fulk, M.}
}