Example 1: Adding citations for books or articles

There are several ways to export citations for books or articles as a BibTeX file. One simple way is to use Google Scholar to obtain a BibTeX entry. For example, if you search for “Bookdown: Authoring Books and Technical Documents with R Markdown”, you can view the citation by clicking on the quote icon underneath the entry:

If you then click on the BibTeX link, you will see the formatted plain text version, which you can download as a file with the .bib extension:

@book{xie2016bookdown,
  title={Bookdown: Authoring Books and Technical Documents with R Markdown},
  author={Xie, Yihui},
  year={2016},
  publisher={CRC Press}
}

To now cite this item in the text of your post, use the format @key, so @xie2016bookdown generates: Xie (2016). Notice that you can click on the year to see the full reference. In order to do this, add this to your YAML front matter:

---
link-citations: true
---

Example 2: Adding cites for R packages using knitr

There is a helper function write_bib() in the knitr package to generate BibTeX entries automatically for R packages. You can use this method to add citations in R Markdown posts in blogdown. The difference is that instead of saving your BibTeX file(s), the write_bib function will create a BibTeX file for you. If you don’t specify a file location, knitr::write_bib will create the file in the /content/post/ directory.

# list specific packages
knitr::write_bib(c("package1", "package2"), "packages.bib")

# or include all used in the post
knitr::write_bib(.packages(), "packages.bib") 

# include all used and specify different location
knitr::write_bib(.packages(), "../../static/bib/packages.bib") 

Add this new BibTeX file (<file-name-here>.bib) to your YAML header:

---
bibliography: [packages.bib] 
---

If you save your BibTeX file(s) to another directory, say in a folder you create like /static/bib/, you would update your YAML header with the correct file path (not in quotes):

---
bibliography: [../../static/bib/packages.bib] 
---

In the text of your post, reference items in the knitr-generated BibTeX file using @R-packagename. For example, in this post, we used several R packages including blogdown (Xie 2017a) and knitr (Xie 2018).

From RStudio’s section on citations, the following markdown text:

1. Blah blah [see @R-blogdown, pp. 33-35; also @R-knitr, ch. 1].

2. Blah blah [@R-blogdown, pp. 33-35].

3. Blah blah [@R-blogdown; @R-knitr].

4. Yihui says blah [-@R-blogdown].

5. @R-blogdown says blah.

Generates these in-text citation styles:

1. Blah blah (see Xie 2017a, 33–35; also Xie 2018, ch. 1).

2. Blah blah (Xie 2017a, 33–35).

3. Blah blah (Xie 2017a; Xie 2018).

4. Yihui says blah (2017a).

5. Xie (2017a) says blah.

Finally, let’s say I want to include a reference to the bookdown package without an in-text citation. To do this, we would include this package in our packages.bib file generated from knitr::write_bib() and referenceed in the YAML header in the post. Then add this to the YAML header:

---
nocite: | 
  @R-bookdown
---

Now you should see the bookdown package reference listed below.