1. Barakat, R. M. and Ekins, R. P. (1961). Assay of Vitamin B12 in blood. Lancet, 2, 25
2. Newmark, P. A. and Gordon, Y. B. (1974). Haematology. Br. Med. Bull., 30, 86
3. Chanarin, I. (1977). Folates, cobalamins and their interrelationship in man. In Marks, V. and Hales, C. N. (eds.) Essays in Medical Biochemistry, Vol. 3, pp. 1–24. ( London: The Biochemical Society and the Association of Clinical Biochemists )
4. Mollin, D. L., Anderson, B. B. and Burman, J. F. (1976). The serum vitamin B12 level: its assay and significance. Clin. Haematol., 5, 521
5. Lau, K. S., Gottlieb, C., Wasserman, L. R. and Herbert, V. (1965). Measurement of serum Vitamin B12 level using radioisotopic dilution and coated charcoal. Blood, 26, 202