\documentclass[
  a4paper,
  11pt,
  liststotoc,
  bibtotoc,
  appendixprefix,
  final]{scrreprt}
  
\usepackage[latin1]{inputenc}
\usepackage[english]{babel}

\usepackage{textcomp}
\usepackage{longtable}

\usepackage{geometry}
\geometry{top=45mm,bottom=50mm,textwidth=142mm}

\usepackage{hyperref}
\usepackage[pdftex]{graphicx}

\usepackage[citestyle=numeric-comp,doi=false,url=false,isbn=false]{biblatex}
\addbibresource{bibliography.bib}
\addbibresource{bibliography_additional.bib}

\setlength{\parindent}{0cm}
\setlength{\parskip}{0.3cm plus0.5mm minus0.5mm}

\newcommand{\HRule}{\rule{\linewidth}{0.25mm}}
\newcommand{\TODO}[1]{\textbf{TODO:} #1}

\begin{document}

%%%

%\frontmatter
\include{title}
% One page completely empty: back side of title page
\newpage
\thispagestyle{empty}
\mbox{}
\pagebreak

\include{abstract}
% One page completely empty: back side of abstract
\newpage
\thispagestyle{empty}
\mbox{}
\pagebreak
\tableofcontents

%%%

%\mainmatter
\include{introduction}

% Methods
\include{methods}
% Results
\include{results}
% Discussion
\include{discussion}

\include{conclusion}

%%%

\appendix
%\listoffigures
%\listoftables
%\bibliographystyle{numeric-comp}
%\bibliography{bibliography}
\printbibliography

\end{document}