@article{Hoaglin1978,
author = {Hoaglin, D.C. and Welsch, R.E.},
title= {The hat matrix in regression and ANOVA},
year = {1978},
doi = {10.2307/2683469},
journal = {The American Statistician},
volume = {32},
number = {1},
pages = {17--22},
}