code: def authors(self):
          
          out = []
          order = 'name surname initials id url'
          auth = namedtuple('Author', order)
          for author in self._citeInfoMatrix.get('author'):
              author = {k.split(":", 1)[-1]: v for k, v in author.items()}
              new = auth(name=author.get('index-name'), id=author.get('authid'),
                         surname=author.get('surname'),
                         initials=author.get('initials'),
                         url=author.get('author-url'))
              out.append(new)
          return out or None
docs: A list of namedtuples storing author information,
          where each namedtuple corresponds to one author.
          The information in each namedtuple is (name surname initials id url).
          All entries are strings.