title: Letter: Free radicals in pyrimidines: e.s.r. of x-irradiated single crystals of phenobarbital.
mesh_terms: D005609:Free Radicals; D010634:Phenobarbital / Q000528:radiation effects*; D011743:Pyrimidines / Q000528:radiation effects*; D011830:Radiation Effects; D011854:Radiochemistry
chemical_list: D005609:Free Radicals; D011743:Pyrimidines; D010634:Phenobarbital