K. Bibliografi

Committee of Revision of the United States Pharmacopoeia Convention Inc. 1995. The United state Pharmacopoeia (USP) 23. The national Formulary (NF) 18. The Board of Trustees, Washington DC..

Standard Methods for The Examination of water and Wastewater, American Public Health Association; American Water Works Association; Water Environment Federation 20Th ed. Washington DC, 1998.