@article{Bates2014,
author = {Bates, D. and Mächler, M. and Bolker, B. and Walker, S.},
title= {Fitting linear mixed-effects models using lme4},
year = {2014},
doi = {10.18637/jss.v067.i01},
URL = {https://doi.org/10.18637/jss.v067.i01.},
volume = {67},
number = {1},
}