def METHOD_NAME(self):
    """ get_columns method returns the columns returned by the API"""
    return [
        'title',
        'type',
        'source',
        'year',
        'pmid',
        'sgr',
        'issn',
        'scopus',
        'doi',
        'pui',
        'authors',
        'keywords',
        'link',
        'id'
    ]