title: Modifiers of non-specific symptoms in occupational and environmental syndromes.
authors.forename: J W
authors.initials: JW
authors.lastname: van der Gulden
authors.forename: P F
authors.initials: PF
authors.lastname: Vogelzang
mesh_terms: D001008:Anxiety Disorders; D015982:Bias; D015986:Confounding Factors, Epidemiologic; D018876:Environmental Illness / Q000209:etiology*; D006801:Humans; D009784:Occupational Diseases / Q000209:etiology*; D012647:Self-Assessment