title: The need for clinical trials registers: a case study in the field of addiction.
authors.forename: E J
authors.initials: EJ
authors.lastname: Wagena
authors.forename: P
authors.initials: P
authors.lastname: Knipschild
mesh_terms: D002986:Clinical Trials as Topic; D006801:Humans; D017594:Publication Bias; D012042:Registries; D019966:Substance-Related Disorders