Maintenance of remission of ulcerative colitis: a comparison between balsalazide 3 g daily and mesalazine 1.2 g daily over 12 months. ABACUS Investigator group. - Green JR; Gibson JA; Kerr GD; Swarbrick ET; Lobo AJ; Holdsworth CD; Crowe JP; Schofield KJ; Taylor MD (Alimentary pharmacology & therapeutics, 1998)