Houyez F (2004). «Active involvement of patients in drug research, evaluation, and commercialization: European perspective». J Ambul Care Manage27 (2): 139–45. doi:10.1097/00004479-200404000-00010. PMID15069992.
Nogales Espert A (2004). «[Rare diseases: a new chapter in medicine]» (στα ισπανικά). An R Acad Nac Med (Madr)121 (1): 139–51, συζήτηση 151–5. PMID15553406.
Houyez F (2004). «Active involvement of patients in drug research, evaluation, and commercialization: European perspective». J Ambul Care Manage27 (2): 139–45. doi:10.1097/00004479-200404000-00010. PMID15069992.