# Bibliographic Citations and Cross-referencing in Latex

While writing an academic paper in Latex, you will definitely need to learn to use references for linking different sections of your paper like subsections, tables, or figures, or for citing an external resource like a paper, website, or codebase.

In Latex, there are broadly three types of references: bibliographic citations, cross-references, and keyword shortcuts.

Bibliographic citations: This is usually used for citing external papers that are not part of the given paper. The most common Latex command used is: \cite{}

Other commands exist like citet, footcite, and misc which control the inline text format where the citation is displayed (within the text, not in the “Reference” section).

Cross-references: This is used for referencing elements internal to the paper like sections, subsections, figures, tables, etc. The most common Latex command used is: \ref{}

Keyword shortcuts: These commands are used to either refer to a popular keyword like the name of your proposed model in the paper, or for adding comments to your paper

We will provide a collection of Latex snippets for each of the three types of references explained: bibliographic citation, cross-referencing, and keyword shortcuts.

### Latex Code Snippets

For adding references to your paper in Latex, there are two ways :

#### 1. Bibliographic citations – \begin{bibliography}

We add the References section always after the Conclusion section, at the end of the paper. We add each reference as a \bibitem, containing the name of a label(here, ref_lncs1). In order to mention this reference in the paper, we write: \cite{ref_lncs1}

\begin{bibliography}
\bibitem{ref_lncs1}
Author, F., Author, S.: Title of a proceedings paper. In: Editor, F., Editor, S. (eds.) CONFERENCE 2016, LNCS, vol. 9999, pp. 1--13. Springer, Heidelberg (2016). \doi{10.10007/1234567890}
\end{bibliography}

#### 2. Bibliographic citations – BibTex

Here, you create a separate .bib file, which is provided as part of the paper template folder that you download. For example, I provide a snapshot of the bibliography file (.bib format) for an IEEE Transactions article.

@article{Hao2014,
title = "Clustering clinical trials with similar eligibility criteria features",
journal = "Journal of Biomedical Informatics",
volume = "52",
pages = "112 - 120",
year = "2014",
issn = "1532-0464",
doi = "https://doi.org/10.1016/j.jbi.2014.01.009",
author = "Tianyong Hao and Alexander Rusanov and Mary Regina Boland and Chunhua Weng",
keywords = "Medical informatics, Clinical trial, Cluster analysis"
}

@article{miller1995wordnet,
title={WordNet: a lexical database for english},
author={Miller, George A},
journal={Communications of the ACM},
doi={10.1145/219717.219748},
volume={38},
number={11},
pages={39--41},
year={1995},
publisher={ACM}
}

We add the following Latex statements at the same position as the \begin{bibliography} command in the previous section, i.e. after the “Conclusion” section and the start of the “References” section.

\bibliography{file_name_bib}
\bibliographystyle{file_name_bst}

Note: When you want to refer to an external website, codebase, or anything other than a research article, you can use the “misc” command and use it similar to a bibliographic citation.

@misc{antidote,
key="antidote",
title={Antidote},
url={https://www.antidote.me/}
}

#### 3. Cross-referencing tables and figures

We use the \label tag to assign the name to the entity (maybe a table, figure, or even a section), by which it will be called or referenced in different parts of the document. Here, instead of \cite which we previously showed for referencing bibliographic references, we will now use \ref to mention or reference a table, figure, or section.

a) We show the performance of the classifier across different feature sets in Table~\ref{table:classificationresults}.
b) In Figure~\ref{fig:workflow}, we provide a detailed workflow of our proposed methodology.
c) We motivate and outline the research challenges and the key contributions of this paper in Section \ref{introduction}.

Let us for example, consider the following templates for a table, figure, and section headings. All of them make use of the \label tag.

##### Tables
\begin{table}
\centering
\caption{Classifier performance results}
\label{table:classificationresults}
\begin{tabular}{|c|c|} \hline
Features (and Models)&amp;Accuracy (in \%)\\ \hline
Baseline 1 (Linear SVM using n-grams)&amp; 59.3\\
Baseline 2 &amp; 64.1\\
Our approach(lexicon based) &amp; 68.4\\
Ensemble SVM model (Optimal) &amp; 69.7\\
\hline\end{tabular}
\end{table}
##### Figures

I will later write an article on how to programmatically create Latex pictures using tikzpicture.

\begin{figure}
\centering
\includegraphics[width=\textwidth]{image_filename}
\caption{Workflow of our proposed methodology}
\label{fig:workflow}
\end{figure}
##### Sections, subsections :
\section{Introduction} \label{introduction}

#### 4. Keyword shortcuts

These commands are global in nature, i.e. they apply across the whole document. They need to be mentioned before the Latex command: \begin{document}

If you want to add a comment regarding a specific line in the paper, simply enclose the contiguous text segment (without any newline character or line separation) in the following manner: \notesr{ sample_text }

\newcommand{\notesr}[1]{\textcolor{red}{SR: #1}}

\newcommand{\new}[1]{\textcolor{blue}{#1}}
##### Placeholder

It is also global in nature and its usage method is the same as the comments that we just discussed prior to this.

For the example below, if you want to use the placeholder within a sentence, you should write it as:

Our proposed model \newpgr{} outperforms the baseline models by a significant margin.

Note: The double braces at the end act as a space after the placeholder text.

\newcommand{\newpgr}{\textsc{metaPGR}}

#### 5. Footnotes:

In the case of a 2-column format, this will appear at the bottom of your column, separated by a line in case. In the case of a single column format like Springer LLCNS, it will appear at the bottom of your page, separated by a single line, starting with a footnote number. This number is also present inline of the text, without any spaces, to indicate the source of the footnote.

To add a footnote inside the text, you use the command : “\footnote{text_content}”

This “text_content” is usually an URL (like a Github repository link), or a sidenote.

If you want the codebase URL to act as a hyperlink (that you can click on) instead of plain text, you need to first import the “url” package and then use the following modified command: “\footnote{\url{link_to_resource}}”

Note: To import any Latex package (url in our case), we add the following line in the main .tex file after the “documentclass” command and before the \begin{document}.

\documentclass[lettersize,journal]{IEEEtran}
...
\usepackage{url}
...
\begin{document}

### Conclusion

We cover how to use bibliographic citations, cross-referencing, keyword shortcuts, and footnotes using Latex while writing a research article.

### Related articles that may be of interest to you

You can get a comprehensive list of academic conferences in the field of AI and Machine Learning in another article written by me

If you are new to writing papers using Latex for academic conferences, you can visit the following articles:

1. I cover how to setup up a Tex environment in your local machine (article link)
2. Conference or journal paper template – individual files and how to use them (article link)