SELECT p.first_name AS contributor_first,p.last_name AS contributor_last,p2.first_name AS enterer_first,p2.last_name AS enterer_last,t.* FROM people p,people p2,samples t,register t2 WHERE t.contributor_no=p.person_no AND t.enterer_no=p2.person_no AND t.sample_no=t2.sample_no AND genus='Ophrypetalum' AND species='odoratum' GROUP BY t.sample_no
