@article{Currie2002,
author = {Currie, I.D. and Durban, M.},
title= {Flexible smoothing with P-splines: A unified approach},
year = {2002},
doi = {10.1191/1471082x02st039ob},
journal = {Statistical Modelling },
volume = {2},
number = {4},
pages = {333--349},
}