# References and citations¶

Because jupyter-book is built on top of Sphinx, there are many ways to reference content within your book (or even across other books, or Sphinx websites). This page has several examples of what you can reference and how to accomplish it.

Tip

You can check for missing references when building a Jupyter Book. To do so, use the following options:

jupyter-book build -W -n --keep-going docs/


This will check for missing references (-n) and turn them into errors (-W), but will still attempt to run the full build (--keep-going), so that you can see all errors in one run.

## Referencing overview¶

Referencing is accomplished with roles or with markdown link syntax, depending on your use-case. There are a few ways to reference content from your book, depending on what kind of content you’d like to reference. Here is a quick overview of some common roles for referencing:

• {ref} is used to reference section labels that you define or figures with a name value

• {numref} is used to provide numbered references to figures, tables, or headers

• {doc} is used to reference other files in your book

• {eq} is used to reference equations that have been given a label value

You can reference a section label through {ref}label  or {ref}some text <label> . Documents can be referenced through {doc}path/to/document  or {doc}some text <path/to/document>

### Numbered references¶

To add a numbered reference to a table, use the {numref} role. If you wish to use custom text, add %s as a placeholder for the number. See the examples in each section below for usage.

## Reference section labels¶

Labels are a way to add tags to parts of your content so that you can reference them later on. This is helpful if you want to quickly insert links to other parts of your book. Labels can be added before major elements of a page, such as titles or figures.

To add a label, use the following pattern before the element you wish to label:

(my-label)=
# The thing to label


For example, we’ve added the following label above the header for this section with:

(content:references)=
## Cross-references and labels


You can insert cross-references to labels in your content with two kinds of syntax:

• {ref}label-text

• [](label-text)

For example, the syntax {ref}content:references or [](content:references) results in a link to this section like so: Reference section labels.

## Referencing figures¶

To reference a figure in your book, first add a figure and ensure that it has both a name as well as a caption associated with it:

source

{figure} ../images/cool.jpg
:name: my-fig-ref

My figure title.



result

Fig. 3 My figure title.

Then, reference the figure by its :name: value. For example:

source

result

Here is {ref}my-fig-ref

Here is My figure title.

Here is {ref}My cool fig <my-fig-ref>

Here is My cool fig

Here is [](my-fig-ref)

Here is My figure title.

Here is [My cool fig](my-fig-ref)

Here is My cool fig

Here is {numref}my-fig-ref

Here is Fig. 3

Here is {numref}Custom Figure %s text 

Here is Custom Figure 3 text

## Reference tables¶

To reference a table, first create a table and ensure that it has a :name: and a title:

source

{table} My table title
:name: my-table-ref

|---|---|
| 3 | 4 |



result

Table 1 My table title

3

4

Here are several ways to reference this content:

source

result

Here is {ref}my-table-ref

Here is My table title

Here is {ref}My cool table <my-table-ref>

Here is My cool table

Here is [](my-table-ref)

Here is My table title

Here is [My cool table](my-table-ref)

Here is My cool table

Here is {numref}my-table-ref

Here is Table 1

Here is {numref}Custom Table %s text 

Here is Custom Table 1 text

## Reference content files¶

To reference other files of book content, use the {doc} role, or link directly to another file with Markdown link syntax. For exmaple:

source

result

Here is {doc}../file-types/myst-notebooks

Here is {doc}A different page <../file-types/myst-notebooks>

Here is A different page

Here is [](../file-types/myst-notebooks.md)

Here is [A different page](../file-types/myst-notebooks.md)

Here is A different page

## Reference equations¶

To reference equations, first insert an equation with a label like so:

(1)$w_{t+1} = (1 + r_{t+1}) s(w_t) + y_{t+1}$

To reference equations, use the {eq} role. It will automatically insert the number of the equation. Note that you cannot modify the text of equation links.

For example:

• See Equation {eq}my-math-ref results in: See Equation (1)

• See Equation [](my-math-ref) results in: See Equation (1).

## Citations and bibliographies¶

You can add citations and bibliographies using references that are stored in a bibtex file that is in your book’s folder. You can then add a citation in-line in your Markdown with the {cite} role, and include the bibliography from your bibtex file with the {bibliography} directive.

This functionality uses the excellent sphinxcontrib-bibtex extension.

1. Create a references bibtex file.

touch references.bib

2. Add references. Add some references to your BibTex file. See the BibTex documentation for information on the BibTex reference style. Here’s an example citation:

@article{perez2011python
,	title	= {Python: an ecosystem for scientific computing}
,	author	= {Perez, Fernando and Granger, Brian E and Hunter, John D}
,	journal	= {Computing in Science \\& Engineering}
,	volume	= {13}
,	number	= {2}
,	pages	= {13--21}
,	year	= {2011}
,	publisher	= {AIP Publishing}
}

3. Add a citation. In your content, use the following syntax to include a citation:

{cite}mybibtexcitation


For example,

{cite}perez2011python


generates this citation: [PGH11]

You can also include multiple citations in one go, like so:

{cite}perez2011python,holdgraf_rapid_2016,RePEc:the:publsh:1367,caporaso2010qiime


becomes [PGH11][HdHP+16][SK14][CKS+10].

4. Add a bibliography. Use the following directive to do so:

{bibliography} path/to/references.bib



This will generate the bibliography of your entire bibtex file. See the bibliography at the end of this page for an example.

When your book is built, the bibliography and citations will now be included.

Warning

If you are adding a bibliography to a different page from your references, then you may need to ensure that page is processed last. Because Sphinx processes pages alphabetically, you may want to name the file zreferences.rst for example.

See this sphinxcontrib-bibtex section for more information.

This feature uses sphinxcontrib-bibtex under the hood, so check its documentation for more information on how to use and configure bibliographies in your book. Do note the documentation is written with rST syntax in mind and you’ll need to adapt the directive/role syntax for your Markdown content.

You can also optionally customize the style of your references. By default, references are displayed in the alpha style. Other currently supported styles include plain, unsrt, and unsrtalpha. These styles create the following bibliography formatting:

• alpha: Use alphanumeric reference labels, citations are sorted by author, year.

• plain: Use numeric reference labels, citations are sorted by author, year.

• unsrt: Use numeric reference labels, citations are sorted by order of appearance.

• unsrtalpha: Use alphanumeric reference labels, citations are sorted by order of appearance.

To set your reference style, use the style option:

{bibliography} path/to/references.bib
:style: unsrt



### Local bibliographies¶

You may wish to include a bibliography listing at the end of each document rather than having a single bibliography contained in a separate document. Having multiple bibliography directives, however, can cause sphinx to issue duplicate citation warnings.

A common fix is to add a filter to the bibliography directives:

{bibliography} path/to/references.bib
:filter: docname in docnames



See sphinxcontrib-bibtex` documentation on local bibliographies.

### Bibliography¶

CKS+10

J Gregory Caporaso, Justin Kuczynski, Jesse Stombaugh, Kyle Bittinger, Frederic D Bushman, Elizabeth K Costello, Noah Fierer, Antonio Gonzalez Pena, Julia K Goodrich, Jeffrey I Gordon, and others. Qiime allows analysis of high-throughput community sequencing data. Nature methods, 7(5):335–336, 2010.

HdHP+16

Christopher Ramsay Holdgraf, Wendy de Heer, Brian N. Pasley, Jochem W. Rieger, Nathan Crone, Jack J. Lin, Robert T. Knight, and Frédéric E. Theunissen. Rapid tuning shifts in human auditory cortex enhance speech intelligibility. Nature Communications, 7(May):13654, 2016. URL: http://www.nature.com/doifinder/10.1038/ncomms13654, doi:10.1038/ncomms13654.

PGH11(1,2)

Fernando Perez, Brian E Granger, and John D Hunter. Python: an ecosystem for scientific computing. Computing in Science \& Engineering, 13(2):13–21, 2011.

SK14

John Stachurski and Takashi Kamihigashi. Stochastic stability in monotone economies. Theoretical Economics, 2014.