TY  - ELEC
A1  - Pinheiro, J.
A1  - Bates, D.
A1  - DebRoy, S.
A1  - Sarkar, D.
A1  - R Core Team
T1  - nlme: Linear and nonlinear mixed effects models: R package version 3.1–131
Y1  - 2017
UR  - http://CRAN.R-project.org/package=nlme
PB  - World Health Organization
CY  - Geneva

ER  -