@article {hall_estimating_2002,
	title = {Estimating and depicting the structure of a distribution of random functions},
	journal = {Biometrika},
	volume = {89},
	number = {1},
	year = {2002},
	pages = {145{\textendash}158},
	url = {http://biomet.oxfordjournals.org/content/89/1/145.short},
	author = {Hall, Peter and Heckman, Nancy E.}
}
