1. Spectrophotometric determination of microamounts of ascorbic acid in citrus fruits
2. ; Vitamin Assay—Tested Methods Verlag Chemie, GmbH, Germany. 1965, 1st edition, p. 227.
3. Official Methods of Analysis (ed.) Association of Official Analytical Chemists, Washington, D. C. 1970, 11th edition, p. 777.
4. The Association of Vitamin Chemists Methods of Vitamin Assay Interscience Publishers, Inc., New York. 1947, 1st edition, p. 144.
5. Technicon Industrial Method number 96–70A 1970.