1. Acculate, Anachemia Chemicals, Ltd., Montreal, Quebec, and Champlain, New York.
2. Determination of Organic Nitrogen by Kjeldahl Method without Distillation
3. American Instrument Co., Inc., “Digestion and Distillation Apparatus for the Micro Kjeldahl Nitrogen Determination,” Bull. No. 2271, Silver Springs, Maryland, 1955.
4. American Society for Testing Materials, ASTM Designation, E 147–59 T (1959).