How to show natbib reference as “first author et al”?

Question

I have a problem with a citation call-out generated with the natbib package

I get this [Y. Kuwata, M. T. Wolf, D. Zarzhitsky and T. L. Huntsberger, 2013]

I would like [Kuwata et al., 2013]

MWE

\documentclass[11pt,a4paper,twoside]{report}
\usepackage[latin1]{inputenc}
\usepackage[left=3.5cm,right=3.5cm,top=3cm,bottom=4cm]{geometry}
\usepackage[english]{babel}
\usepackage[square, authoryear]{natbib}
\bibliographystyle{chicago}

\begin{document}
I get this  \citep{VO}  
[Y. Kuwata, M. T. Wolf, D. Zarzhitsky and T. L. Huntsberger, 2013]

I would like [Kuwata et al., 2013]
%%%%%%%%%%% Bibliography%%%%%%%%%%%%%%%%
\addcontentsline{toc}{chapter}{References}
\bibliography{Sample} 

\end{document}

My Sample.bib

@article{VO,
    author =       "{Y. {Kuwata}, M. T. {Wolf}, D. {Zarzhitsky} and T. L. {Huntsberger}}",    
    title =        "{\emph{Safe Maritime Autonomous Navigation With COLREGS, Using Velocity Obstacles}}",
    journal =      {IEEE Journal of Oceanic Enginerring} ,
    volume =       {39},
    number =       {1},
    pages =        {110 - 119},
    year =         {2013},
    DOI =          {10.1109/JOE.2013.2254214}
}

I have looked around, and tried different things that I found (in here) as changing plainnat to chicago

Am I all wrong or is it not possible to do this with natbib?

I want to keep the bibliography with all names, year, title, journal, volume, number, pages. but add DOI at the last as a hyperlink

Answer 1

According to how you input the data, BibTeX sees just one author of your paper, because there's an additional pair of braces that shouldn't be there. Also, the different authors should be separated by the keyword “and”.

Here's the proper code:

author = "Y. Kuwata and M. T. Wolf and D. Zarzhitsky and T. L. Huntsberger",