It depends on what exactly you need, but a good starting point is to use the DOI of your paper and access the API of CrossRef. You will then see the metadata attached to that paper. Most publishers also provide so-called 'open citations' with these metadata.

Here is one example: https://api.crossref.org/works/10.1016/j.gloenvcha.2021.102386

(Note: This is a machine-readable JSON-format; if you only see messy stuff, use a "JSON Beautifier" - either as a browser extension, or you can simply copy the whole JSON text into an online JSON formatter.)

Go to the "reference"-tag. You will see a list of references there. Here is a screenshot of the first three references (the first is from the journal Business History Review, the third is from the journal Critical Inquiry, etc.):

If the references carry DOIs, you can use these DOI to again access the CrossRef API and find out, say, the authors' ORCID (and their names, date of publication, journal names etc). That way, you could calculate which authors are cited most often in a text, or even in a larger corpus of thousands of papers.

Make sure to read the CrossRef REST API Documentation.

Regarding your possible use-case of "which reference is referred to most often throughout the text" - - this seems a bit tricky, as you will need to computationally access the full texts. Well, there are indeed large corpora of full-texts of Open Access papers, which might be helpful for you. But anyway, whatever the actual detail you wish to achieve, the CrossRef API and its open scholarly metadata (open citations) is always a good starting point.

It depends on what exactly you need, but a good starting point is to use the DOI of your paper and access the API of CrossRef. You will then see the metadata attached to that paper. Most publishers also provide so-called 'open citations' with these metadata.

Here is one example: https://api.crossref.org/works/10.1016/j.gloenvcha.2021.102386

(Note: This is a machine-readable JSON-format; if you only see messy stuff, use a "JSON Beautifier" - either as a browser extension, or you can simply copy the whole JSON text into an online JSON formatter.)

Go to the "reference"-tag. You will see a list of references there. Here is a screenshot of the first three references (the first is from the journal Business History Review, the third is from the journal Critical Inquiry, etc.):

If the references carry DOIs, you can use these DOI to again access the CrossRef API and find out, say, the authors' ORCID (and their names, date of publication, journal names etc). That way, you could calculate which authors are cited most often in a text, or even in a larger corpus of thousands of papers.

Regarding your possible use-case of "which reference is referred to most often throughout the text" - - this seems a bit tricky, as you will need to computationally access the full texts. Well, there are indeed large corpora of full-texts of Open Access papers, which might be helpful for you. But anyway, whatever the actual detail you wish to achieve, the CrossRef API and its open scholarly metadata (open citations) is always a good starting point.

Make sure to read the CrossRef REST API Documentation. For more information on open citations, I suggest the I4OC.