title: Variations in LD50-30 in a strain of rats over 20 years.
mesh_terms: D000818:Animals; D004307:Dose-Response Relationship, Radiation; D005260:Female; D008297:Male; D011833:Radiation Injuries, Experimental / Q000401:mortality*; D051381:Rats; D011919:Rats, Inbred Strains; D013997:Time Factors