title: Letter: Methotrexate-citrovorum factor in treating osteogenic sarcoma.
mesh_terms: D004359:Drug Therapy, Combination; D006801:Humans; D002955:Leucovorin / Q000008:administration & dosage* / Q000627:therapeutic use; D008727:Methotrexate / Q000008:administration & dosage* / Q000627:therapeutic use; D012516:Osteosarcoma / Q000188:drug therapy*
chemical_list: D002955:Leucovorin; D008727:Methotrexate