title: Study of crystalline drugs by means of polarizing microscope. III. Key refractive indices of some crystalline drugs and their measurement using an improved immersion method.
mesh_terms: D001241:Aspirin / Q000032:analysis; D003461:Crystallography / Q000379:methods; D008859:Microscopy, Polarization / Q000379:methods; D004364:Pharmaceutical Preparations / Q000032:analysis*
chemical_list: D004364:Pharmaceutical Preparations; D001241:Aspirin