PLOS ONE
['Opium and bladder cancer: A systematic review and meta-analysis of the odds ratios for opium use and the risk of bladder cancer.', 'International variations in bladder cancer incidence and mortality.', 'Mahmood Moosazadeh', 'PLOS ONE', 'Creative Commons Attribution 4.0 International', 'Opium and bladder cancer: A systematic review and meta-analysis of the odds ratios for opium use and the risk of bladder cancer.']