deal with BibTeX information

[sotetsuk]

WHY

To acquire the author information, we must get the BibTeX information.

How

1. Naive solution

See release v0.0.1-alpha

func (a *Article) crawlAndParseBibTeX() {
    popURL, err := CitePopUpQuery(a.InfoId)
    if err != nil {
        log.Fatal(err)
    }
    popDoc, err := goquery.NewDocument(popURL)
    if err != nil {
        log.Fatal(err)
    }
    bibURL, _ := popDoc.Find("#gs_citi > a:first-child").Attr("href")
    bibDoc, err := goquery.NewDocument(SCHOLAR_URL + bibURL)
    if err != nil {
        log.Fatal(err)
    }
    a.Bibtex = bibDoc.Text()
}

2. scholar.py's solution

1. send request to GET_SETTINGS_URL of scholar.py#L939
   
2. send request to SET_SETTINGS_URL of scholar.py#L969
3. Import into BibTeX emerges. scholar.py#L457 scholar.py#L994

3. hildensia/scholar.py's solution

• scholar.py#L201
• Using "Import from BibTeX" by sending request with this header (?):

headers = {
    'User-Agent': self.UA,
    'Cookie': 'GSP=ID=%(ID)s:CF=%(CF)d' % {
         "ID": self.GID,
         "CF": self.cite_format
    }
}

4. gscholar's solution

Access directly to

https://scholar.google.com/scholar.bib?q=info:0qfs6zbVakoJ:scholar.google.com/&output=citation

See: https://github.com/5kg/gscholar/blob/master/lib/gscholar/paper.rb

This solution fails:

## Related - [scholar.py](https://github.com/ckreibich/scholar.py) - [gscholar](https://libraries.io/rubygems/gscholar)