99-refs.Rmd

`r if (knitr:::is_html_output()) '
# References {-}
'`

```{r include=FALSE}
# automatically create a bib database for R packages
knitr::write_bib(c(.packages(), 
                   'bookdown',
                   'knitr', 
                   'rmarkdown'), 
                 'packages.bib')
```