3Hanauer S, Schwartz J, Robinson M, etc. Mesalazine capsules for the treatment of active colitis: results of a controlled trial. Am J Gastroenterology, 1993, 88(8) :1188
4Norris etc. Process of making aminosalicylic acid[P]. US 1542265, 1925-06-16
5Noruberuto Maiyaa. Production of highly pure 5-amino salicylic acid[P]. JP 6340600, 1994-12-13
6Sjostrand. Method of preparing 5-amino salicylic acid[P]. US 4788331, 1988-11-29