I noticed that first names in references are treated differently between output formats. For example, in the bookdown-demo repo, HTML renders

Xie, Yihui. 2015. Dynamic Documents with R and Knitr. 2nd ed. Boca Raton, Florida: Chapman; Hall/CRC. http://yihui.name/knitr/.

and PDF renders:

Xie, Y. (2015). Dynamic Documents with R and knitr. Chapman and Hall/CRC, Boca Raton, Florida, 2nd edition. ISBN 978-1498716963.

I prefer the latter. Short of modifying all of the entries in my bib file, is there a way to get consistency (or at least force abbreviation)?