main.tex:

\documentclass{article}
\usepackage[utf8]{inputenc}
\usepackage{natbib}
\bibliographystyle{agsm}

%Cheat-sheet för referenskommandon
%https://www.imperial.ac.uk/media/imperial-college/administration-and-support-services/library/public/LaTeX-example-Harvard-apr-2019.pdf


\title{TDA497 - Home Exam}
\author{Oskar Lyrstrand}
\date{October 2019}


\setlength{\parindent}{0pt}
\setlength{\parskip}{0.5em}

\begin{document}

\maketitle

\section{Introduction}
In this \cite{Traffic}

\newpage
\bibliography{sources}

\end{document}

library.bib:

@article{Traffic,
   author = {Kim, Y. and Falletta, J. and Kelly, S.},
   title = {Traffic is complex, but modelling using deceptively simple rules can help unravel what's going on},
   url = {https://theconversation.com/traffic-is-complex-but-modelling-using-deceptively-simple-rules-can-help-unravel-whats-going-on-92833},
   year = {2018-06-07},
   type = {Journal Article},
   urldate = {2019-05-16}
}