Citation in two column document

Question

I'm using the Springer template by \documentclass[twocolumn]{svjour3}. I'd like to use the citation by \cite{} with the column break. As can be seen in the figure below the citations are pushing the limits.

\RequirePackage{fix-cm}
\documentclass[twocolumn]{svjour3}          % twocolumn
\smartqed  % flush right qed marks, e.g. at end of proof
\usepackage{graphicx}

\begin{document}

\title{Insert your title here%\thanks{Grants or other notes
%about the article that should go on the front page should be
%placed here. General acknowledgments should be placed at the end of the article.}
}
\subtitle{Do you have a subtitle?\\ If so, write it here}

\author{First Author         \and
        Second Author %etc.
}

%\authorrunning{Short form of author list} % if too long for running head

\institute{F. Author \at
              first address \\
              Tel.: +123-45-678910\\
              Fax: +123-45-678910\\
              \email{fauthor@example.com}           %  \\
%             \emph{Present address:} of F. Author  %  if needed
           \and
           S. Author \at
              second address
}

\date{Received: date / Accepted: date}
\end{document}

Answer 1

Add

\usepackage{breakcites}

to your preamble to make the citation markers break at the end of the lines. If this does not work, see more options here. Here is an example, modified from the SVJour3 template here:

%%%%%%%%%%%%%%%%%%%%%%% file template.tex %%%%%%%%%%%%%%%%%%%%%%%%%
%
% This is a general template file for the LaTeX package SVJour3
% for Springer journals.          Springer Heidelberg 2010/09/16
%
% Copy it to a new file with a new name and use it as the basis
% for your article. Delete % signs as needed.
%
% This template includes a few options for different layouts and
% content for various journals. Please consult a previous issue of
% your journal as needed.
%
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%
%
\RequirePackage{fix-cm}
\documentclass[twocolumn]{svjour3}          % twocolumn
%
\smartqed  % flush right qed marks, e.g. at end of proof
%
\usepackage{graphicx}
\usepackage{breakcites}
\usepackage{blindtext}
%
\begin{document}

\title{Insert your title here}
%\thanks{Grants or other notes
%about the article that should go on the front page should be
%placed here. General acknowledgments should be placed at the end of the article.}

%\titlerunning{Short form of title}        % if too long for running head

\author{First Author         \and
        Second Author %etc.
}

%\authorrunning{Short form of author list} % if too long for running head

\institute{F. Author \at
              first address \\
              Tel.: +123-45-678910\\
              Fax: +123-45-678910\\
              \email{fauthor@example.com}           %  \\
%             \emph{Present address:} of F. Author  %  if needed
           \and
           S. Author \at
              second address
}

\date{Received: date / Accepted: date}
% The correct dates will be entered by the editor


\maketitle

\begin{abstract}
Too abstract.
\end{abstract}

\section{Citations in left column}
\label{sec:1}
Text with citations that break lines \cite{RefB} and \cite{RefJ}.

\section{Blind text}
\blindtext[2]

\section{Citations in right column}
These citations also break properly~\cite{RefJ} and~\cite{RefB}.


% Non-BibTeX users please use
\begin{thebibliography}{Author, 2017}
%
% and use \bibitem to create references. Consult the Instructions
% for authors for reference list style.
%
\bibitem[Extremely Long Author Name, 2017]{RefJ}
% Format for Journal Reference
Author, Article title, Journal, Volume, page numbers (2017)
% Format for books
\bibitem[Slightly Shorter Author Name, 2018]{RefB}
Author, Book title, page numbers. Publisher, place (year)
% etc
\end{thebibliography}

\end{document}
% end of file template.tex