\chapter{Another chapter}
\label{cha:another_chapter}

This is a reference to Chapter~\ref{cha:a_chapter}.\footnote{Footnotes are numbered on a per-chapter basis.} In particular, Section~\ref{sec:a_section} talks about code and math. I'm particularly partial to Listing~\ref{code:hello_world} and Eq.~\eqref{eq:stokes_theorem}.