def return_authors(paper):
    """ Return the author list from the paper nest"""
    authorlist = []
    try:
        for author in paper['MedlineCitation']['Article']['AuthorList']:
            try:
                authorlist.append(author['LastName'] + ', ' +
                                  author['ForeName'])
            except ValueError:
                pass
    except KeyError:
        pass
    return str(authorlist)