1. The research subject as wage earner;Anderson;Theor. Med. Bioeth.,2002
2. Responsibilities of sponsors are limited in premature discontinuation of trials;Ashcroft;BMJ,2001
3. Study of the motivation of physicians participating in public health research;Cogneau;Groupe de Recherche, DESIR. Sante Publique,2002
4. Participation in clinical drug studies: motivations and barriers;Cunny;Clin. Ther.,1994
5. Incentives for research participants;Dickert,2008