Remove blank page for beamer using natbib in Rmarkdown - r

Question

My little example (test.rmd) is as follows:
---
output:
beamer_presentation:
latex_engine: xelatex
citation_package: natbib
bibliography: ref.bib
biblio-style: "unsrtnat"
colorlinks: yes
---
## Papers
- Cp #mallows1973some
- AIC #akaike1974new
- BIC #schwarz1978estimating
- GCV #craven1978smoothing
- bridge #frank1993statistical
- LASSO #tibshirani1996regression
- SCAD #fan2001variable
- MCP #zhang2010nearly
## References {.allowframebreaks}
where ref.bib is
#Article{mallows1973some,
author = {Mallows, Colin L.},
journal = {Technometrics},
title = {{Some comments on $C_p$}},
year = {1973},
number = {1},
pages = {87--94},
volume = {42},
}
#Article{akaike1974new,
author = {Akaike, Hirotugu},
journal = {IEEE Transactions on Automatic Control},
title = {A new look at the statistical model identification},
year = {1974},
number = {6},
pages = {716--723},
volume = {19},
}
#Article{schwarz1978estimating,
author = {Schwarz, Gideon},
journal = {The Annals of Statistics},
title = {Estimating the dimension of a model},
year = {1978},
number = {2},
pages = {461--464},
volume = {6},
publisher = {Institute of Mathematical Statistics},
}
#Article{craven1978smoothing,
author = {Craven, Peter and Wahba, Grace},
journal = {Numerische Mathematik},
title = {Smoothing noisy data with spline functions},
year = {1978},
number = {4},
pages = {377--403},
volume = {31},
}
#Article{frank1993statistical,
author = {Frank, Ildiko E. and Friedman, Jerome H.},
journal = {Technometrics},
title = {A statistical view of some chemometrics regression tools},
year = {1993},
number = {2},
pages = {109--135},
volume = {35},
}
#Article{tibshirani1996regression,
author = {Tibshirani, Robert},
title = {Regression shrinkage and selection via the lasso},
journal = {Journal of the Royal Statistical Society. Series B (Methodological)},
year = {1996},
volume = {58},
number = {1},
pages = {267--288},
publisher = {JSTOR},
}
#Article{fan2001variable,
author = {Fan, Jianqing and Li, Runze},
journal = {Journal of the American Statistical Association},
title = {Variable selection via nonconcave penalized likelihood and its oracle properties},
year = {2001},
number = {456},
pages = {1348--1360},
volume = {96},
}
#Article{zhang2010nearly,
author = {Zhang, Cun-Hui},
journal = {The Annals of Statistics},
title = {Nearly unbiased variable selection under minimax concave penalty},
year = {2010},
number = {2},
pages = {894--942},
volume = {38},
}
My problem is that test.rmd can run successfully while there is a blank page in the second page.
One may suggest that I can use the csl: xxx.csl instead of citation_package: natbib in Rmarkdown for beamer. Surely, csl: xxx.csl is fine and can run without accidents, but I still prefer to using citation_package: natbib.
Curiously, if I change ## References {.allowframebreaks} in test.rmd with
`r if (knitr::is_html_output()) '
## References {.allowframebreaks}
'`
then the blank page disappears. However, a new problem has emerged; the frame title and the bookmark of References both disappear. How can I fix the problems?

Answer 1

Quick hack:
---
output:
beamer_presentation:
latex_engine: xelatex
keep_tex: true
citation_package: natbib
bibliography: ref.bib
biblio-style: "unsrtnat"
colorlinks: yes
header-includes:
- \pretocmd{\bibliographytrue}{\frametitle{References}}{}{}
---
## Papers
- Cp #mallows1973some
- AIC #akaike1974new
- BIC #schwarz1978estimating
- GCV #craven1978smoothing
- bridge #frank1993statistical
- LASSO #tibshirani1996regression
- SCAD #fan2001variable
- MCP #zhang2010nearly

Answer 2

Using # References instead of ## References solves this problem.
---
output:
beamer_presentation:
latex_engine: xelatex
citation_package: natbib
bibliography: ref.bib
biblio-style: "unsrtnat"
colorlinks: yes
---
## Papers
- Cp #mallows1973some
- AIC #akaike1974new
- BIC #schwarz1978estimating
- GCV #craven1978smoothing
- bridge #frank1993statistical
- LASSO #tibshirani1996regression
- SCAD #fan2001variable
- MCP #zhang2010nearly
# References