1. , and , Food Industries Manual, 19th ed., p. 1009–1011. Leonard Hill Books, London 1962.
2. Unicam SP 90 Atomic Absorption Spectrophotometer, McGrand-Hill Book Company, Inc., New York and London 1960.
3. and , Food values ofportions commonly used, 11th ed., p. 50. J. B. Lippincott Company, Philadelphia, Toronto 1969.
4. The Design and Analysis of Experiments. John Wiley and Sons, Inc., New York and London 1962.
5. and , The Composition of Foods, 5th ed., p. 45–46. Her Majesty's Stationery Office, London 1960.