title: Virus particles in rat leukemias induced by N-nitrosobutylurea.
mesh_terms: D000284:Administration, Oral; D000818:Animals; D002073:Butanes / Q000008:administration & dosage; D002273:Carcinogens / Q000008:administration & dosage; D007942:Leukemia, Experimental / Q000139:chemically induced* / Q000382:microbiology; D008854:Microscopy, Electron; D009607:Nitrosourea Compounds / Q000008:administration & dosage; D009858:Oncogenic Viruses / Q000302:isolation & purification*; D012328:RNA Viruses / Q000302:isolation & purification*; D051381:Rats
chemical_list: D002073:Butanes; D002273:Carcinogens; D009607:Nitrosourea Compounds