@article {Crai:Rupp:like:2004, title = {Likelihood Ratio Tests in Linear Mixed Models with One Variance Component}, journal = {Journal of the Royal Statistical Society, Series B: Statistical Methodology}, volume = {66}, number = {1}, year = {2004}, pages = {165{\textendash}185}, keywords = {Degrees of freedom, Non-regular problems, penalized splines}, author = {Crainiceanu, C and Ruppert, D.} }