check_doi               Check for valid DOI
construct_or_url        OpenRetractions URL
find_doi                Find DOIs in strings
get_date                Convert timestamp to Date
query_or                Query <URL: http://openretractions.com> for
                        retractions
retractcheck            retractcheck: Retraction scanner
retractcheck_dir        Check files in directory for retractions
retractcheck_docx       Check docx file for retractions
retractcheck_html       Check html file for retractions
retractcheck_pdf        Check pdf file for retractions
retractcheck_rtf        Check rtf file for retractions
retractcheck_txt        Check txt file for retractions
