Letter: Value of uncontrolled trials in use of sulfasalazine.
D003093:Colitis, Ulcerative / Q000188:drug therapy; D003424:Crohn Disease / Q000188:drug therapy; D004341:Drug Evaluation; D006801:Humans; D012107:Research Design; D012460:Sulfasalazine / Q000627:therapeutic use*
D012460:Sulfasalazine