R 如何使用json格式收集引用类型每年的卷数？

参考书目的格式如下：

@article{alvarez2015skillrank,
  title={Skillrank: Towards a hybrid method to assess quality and confidence of professional skills in social networks},
  author={{\'A}lvarez-Rodr{\'\i}guez, Jose Mar{\'\i}a and Colomo-Palacios, Ricardo and Stantchev, Vladimir},
  journal={Scientific Programming},
  volume={2015},
  pages={3},
  year={2015},
  publisher={Hindawi Publishing Corp.}
}

@inproceedings{arora2017supporting,
  title={Supporting collaborative software development in academic learning environment: A collaborative pair and quadruple programming based approach},
  author={Arora, Ritu and Goel, Sanjay and Mittal, RK},
  booktitle={2017 Tenth International Conference on Contemporary Computing (IC3)},
  pages={1--7},
  year={2017},
  organization={IEEE}
}

@inproceedings{bachrach2015human,
  title={Human judgments in hiring decisions based on online social network profiles},
  author={Bachrach, Yoram},
  booktitle={2015 IEEE International Conference on Data Science and Advanced Analytics (DSAA)},
  pages={1--10},
  year={2015},
  organization={IEEE}
}

如何能够生成一个每年都有文章和会议数量的数据框架

举例说明

year, article, conference
2015,1,1,
2016,0,0
2017,0,1

---

使用RefManageR包将文件nathalie.bib读入R，然后将其转换为数据帧，并执行计数，指定要分组的变量

library(dplyr)
library(RefManageR)

"nathalie.bib" %>%
  ReadBib %>%
  as.data.frame %>%
  count(bibtype, year)

给予：

# A tibble: 3 x 3
  bibtype       year      n
  <chr>         <chr> <int>
1 Article       2015      1
2 InProceedings 2015      1
3 InProceedings 2017      1

       bibtype
year    Article InProceedings total
  2015        1             1     2
  2017        0             1     1
  total       1             2     3

给予：

# A tibble: 3 x 3
  bibtype       year      n
  <chr>         <chr> <int>
1 Article       2015      1
2 InProceedings 2015      1
3 InProceedings 2017      1

       bibtype
year    Article InProceedings total
  2015        1             1     2
  2017        0             1     1
  total       1             2     3

---

看起来像bibtex文件-尝试搜索“R bibtex解析器”-对于应该能够处理此问题的现有软件包，似乎有一些选项-例如：