title: On the distribution of the time required to remove white balls from an urn.
mesh_terms: D003037:Cobalt Radioisotopes; D004781:Environmental Exposure; D006801:Humans; D008433:Mathematics; D008954:Models, Biological; D009784:Occupational Diseases / Q000517:prevention & control; D011835:Radiation Protection
chemical_list: D003037:Cobalt Radioisotopes