title: Aspects of collaboration relating to follow-up-studies.
mesh_terms: D005500:Follow-Up Studies; D006801:Humans; D007391:International Cooperation; D009381:Neoplasms, Radiation-Induced / Q000209:etiology; D013223:Statistics as Topic; D013911:Thorium Dioxide / Q000009:adverse effects*
chemical_list: D013911:Thorium Dioxide