Retrieve citations of a journal paper using R

Question

Using R, I want to obtain the list of articles referencing to a scientific journal paper.

The only information I have is the title of the article, e.g. "Protein measurement with the folin phenol reagent".

Is anyone able to help me by producing a replicable example that I can use?

Here is what I tried so far.

The R package fulltext seems to be useful, because it allows to retrieve a list of IDs linked to an article. For instance, I can get the article's DOI:

library(fulltext)
res1 <- ft_search(query = "Protein measurement with the folin phenol reagent", from = "crossref")
res1 <- ft_links(res1)
res1$crossref$ids

In the same way, I can get the scopus id, by setting from = "scopus" in the function fulltext::ft_search (and by including a scopus API key).

If using the DOI, I can obtain the number of citations of the article using the R library rcrossref:

rcrossref::cr_citation_count(res1$crossref$ids[1])

Similarly, I can use the R package rscopus if I want to use the scopus id, rather than the DOI.

Unfortunately, this information is not sufficient to me, as I need the list of articles referencing to the paper, not the number.

I saw on the internet many people using the package scholar. But if I understand correctly, for this to work I need article's authors to have a google scholar ID, and I have to find a way to retrieve this ID. So it doesn't look like a viable solution.

Does anyone has any idea on how to solve this problem?

Answer 1

Once you have the DOI, you can use the OpenCitations API to fetch data about publications that cite the article. Access the API with the rjson-package via https://opencitations.net/index/coci/api/v1/citations/{DOI}. The field name citing contains as values the DOIs of all publications that cite the publication. You can then use CrossRef's API to fetch further metadata about the citing papers, such as titles, journal, publication date and authors (via https://api.crossref.org/works/{DOI}).

Here is an example of OpenCitations' API with three citations (as of January 2021).

---

Here is a possible code (with the same example as above):

opcit <- "https://opencitations.net/index/coci/api/v1/citations/10.1177/1369148118786043"

result <- rjson::fromJSON(file = opcit)

citing <- lapply(result, function(x){
  x[['citing']]
})
# a vector with three DOIs, each of which cite the paper
citing <- unlist(citing) 

Now we have the vector citing with three DOIs. You can then use rcrossref to find out basic information about the citing papers, such as:

paper <- rcrossref::cr_works(citing[1])

# find out the title of that paper
paper[["data"]][["title"]]

# output: "Exchange diplomacy: theory, policy and practice in the Fulbright program"

Since you have a vector of DOIs in citing, you could also use this approach:

citingdata <- rcrossref::cr_cn(citing)

The output of citingdata should lead to the metadata of the three citing papers, structured like in these two examples:

[[1]]
[1] "@article{Wong_2020,\n\tdoi = {10.1017/s1752971920000196},\n\turl = {https://doi.org/10.1017%2Fs1752971920000196},\n\tyear = 2020,\n\tmonth = {jun},\n\tpublisher = {Cambridge University Press ({CUP})},\n\tpages = {1--31},\n\tauthor = {Seanon S. Wong},\n\ttitle = {One-upmanship and putdowns: the aggressive use of interaction rituals in face-to-face diplomacy},\n\tjournal = {International Theory}\n}"

[[2]]
[1] "@article{Aalberts_2020,\n\tdoi = {10.1080/21624887.2020.1792734},\n\turl = {https://doi.org/10.1080%2F21624887.2020.1792734},\n\tyear = 2020,\n\tmonth = {aug},\n\tpublisher = {Informa {UK} Limited},\n\tvolume = {8},\n\tnumber = {3},\n\tpages = {240--264},\n\tauthor = {Tanja Aalberts and Xymena Kurowska and Anna Leander and Maria Mälksoo and Charlotte Heath-Kelly and Luisa Lobato and Ted Svensson},\n\ttitle = {Rituals of world politics: on (visual) practices disordering things},\n\tjournal = {Critical Studies on Security}\n}"