Linear Mixed-Effects Models -- Linear Mixed-Effects Models: Basic Concepts and Examples -- Theory and Computational Methods for Linear Mixed-Effects Models -- Describing the Structure of Grouped Data -- Fitting Linear Mixed-Effects Models -- Extending the Basic Linear Mixed-Effects Model -- Nonlinear Mixed-Effects Models -- Nonlinear Mixed-effects Models: Basic Concepts and Motivating Examples -- Theory and Computational Methods for Nonlinear Mixed-Effects Models -- Fitting Nonlinear Mixed-Effects Models