\TUappendix{THE FIRST APPENDIX}
\label{App:A}
\TUappendix{THE SECOND APPENDIX}
\label{App:B}
\TUsection{A Heading in an Appendix}
\TUsubsection{A Subheading in an Appendix}
\TUsubsubsection{A Sub-subsection in an Appendix} 
