code: def get_links(html, outformat):
      
      if outformat == FORMAT_BIBTEX:
          refre = re.compile(r'<a href="https://scholar.googleusercontent.com(/scholar\.bib\?[^"]*)')
      elif outformat == FORMAT_ENDNOTE:
          refre = re.compile(r'<a href="https://scholar.googleusercontent.com(/scholar\.enw\?[^"]*)"')
      elif outformat == FORMAT_REFMAN:
          refre = re.compile(r'<a href="https://scholar.googleusercontent.com(/scholar\.ris\?[^"]*)"')
      elif outformat == FORMAT_WENXIANWANG:
          refre = re.compile(r'<a href="https://scholar.googleusercontent.com(/scholar\.ral\?[^"]*)"')
      reflist = refre.findall(html)
      # escape html entities
      reflist = [re.sub('&(%s);' % '|'.join(name2codepoint), lambda m:
                        chr(name2codepoint[m.group(1)]), s) for s in reflist]
      return reflist
docs: Return a list of reference links from the html.
  
      Parameters
      ----------
      html : str
      outformat : int
          the output format of the citations
  
      Returns
      -------
      List[str]
          the links to the references