\chapter{Sample Appendix}

Just more \index{sample text}sample text.

$x \equiv y$ 

\begin{equation}
  \label{eq:test}
  a + b
\end{equation}
\ref{eq:test}
\eqref{eq:test}
\cref{eq:test}

\nocite{*}

\cref{lemma:xxx}

\chapterbib