@article {Grev:Crai:Kche:Pete:rest:2008,
	title = {Restricted Likelihood Ratio Testing for Zero Variance Components in Linear Mixed Models},
	journal = {Journal of Computational and Graphical Statistics},
	volume = {17},
	number = {4},
	year = {2008},
	pages = {870{\textendash}891},
	keywords = {Nonparametric smoothing, nonregular problem, parametric bootstrap, penalized splines},
	author = {Greven, S. and Crainiceanu, C and K{\"u}chenhoff, Helmut and Peters, Annette}
}
