main.tex

\documentclass[a4paper, 11pt, titlepage, twoside, openany]{book}
\usepackage{plain}
\usepackage{setspace}
% Layout
\usepackage[
  paperheight=29.7cm,
  paperwidth=21cm,
  outer=1.5cm,
  inner=2.5cm,
  top=2cm,
  bottom=2cm
]{geometry}
% Chapter
\usepackage{titlesec}
\singlespacing
\setcounter{secnumdepth}{3}
\setcounter{tocdepth}{3}
% Letter
\usepackage[utf8]{inputenc}
% Language
\usepackage[english]{babel}
% PDF/A
\usepackage[a-1b]{pdfx}
% Image
\usepackage{graphicx}
\usepackage{wrapfig}
\usepackage{stackengine}
\usepackage{etoolbox}
\BeforeBeginEnvironment{wrapfigure}{\setlength{\intextsep}{0pt}}
% Hyperlink
\usepackage{xurl}
\usepackage[pdfa]{hyperref}
\hypersetup{breaklinks=true}
% List
\usepackage{enumitem}

% START: DELETE ME
\usepackage{lipsum}
% END: DELETE ME

% Document
\begin{document}
  % Cover
  \pagenumbering{gobble}
  \input{etc/cover}
  \clearpage

  % Acknowledgements
  \input{etc/acknowledgements}
  \clearpage
  \pagestyle{plain}

  % Table of Contents
  \frontmatter
  \pagenumbering{Roman}
  \tableofcontents
  \clearpage
  \begingroup
  \pagestyle{empty}
  \cleardoublepage
  \endgroup

  % Start page numbering
  \mainmatter

  % Group to define space between chapters
  \begingroup
  % Override format of title chapter
  \titleformat{\chapter} {\normalfont\Huge\bfseries}{\thechapter}{1em}{} \titlespacing*{\chapter}{0pt}{0.59in}{0.02in}
  \titlespacing*{\section}{0pt}{0.20in}{0.02in} \titlespacing*{\subsection}{0pt}{0.10in}{0.02in}
  \titlespacing*{\subsubsection}{0pt}{0.05in}{0.02in}

  % Abstract
  \input{etc/abstract.tex}

  % Chapters
  \input{chapters/examples.tex}

  % Conclusions
  \input{etc/conclusions.tex}

  \endgroup

  % Bibliography
  \addcontentsline{toc}{chapter}{Bibliography}
  % Alphabetical order of authors
  \bibliographystyle{plain}
  \bibliography{bibliography.bib}

  % Attachments
  \titleformat{\chapter} {\normalfont\Huge\bfseries}{Appendix \thechapter}{1em}{}
  \appendix
  \input{attachments/attachment.tex}
\end{document}