title: Ammonium acid urate in human urinary calculi.
mesh_terms: D006801:Humans; D008855:Microscopy, Electron, Scanning; D000644:Quaternary Ammonium Compounds / Q000032:analysis; D014527:Uric Acid / Q000032:analysis*; D014545:Urinary Calculi / Q000652:urine*; D014961:X-Ray Diffraction
chemical_list: D000644:Quaternary Ammonium Compounds; D014527:Uric Acid