@article {Crai:Rupp:Clae:Wand:exac:2005,
	title = {Exact Likelihood Ratio Tests for Penalised Splines},
	journal = {Biometrika},
	volume = {92},
	number = {1},
	year = {2005},
	pages = {91{\textendash}103},
	keywords = {Linear mixed model, Penalised spline, Smoothing, Zero variance component},
	author = {Crainiceanu, C and Ruppert, D. and Claeskens, Gerda and Wand, M. P.}
}
