1. S. W. Bailey and J. E. Ayling “Chemistry and Biology of Pteridines,” ed. by W. Pfleiderer, Walter de Gruyter, Berline, New York, 1975, pp. 633–643.
2. T. Fukushima and J. C. Nixon, “Chemistry and Biology of Pteridines,” ed. by R. L. Kisliuk and G.M. Brown, Elsevier, North-Holland, Inc., 1979, pp. 35–36.
3. R. L. Blakley, “The Biochemistry of Folic Acid and Related Pteridines,” North-Holland, Amsterdam, 1969.
4. H. Rembold, “Vitamins and Hormones,” Vol. 23, ed. by R. S. Haris, I. G. Wool and J. A. Loraine, Academic Press Inc., New York, 1965 pp. 359–382.
5. G. M. Brown, J. Yim, Y. Suzuki, M. C. Heine and F. Foor “Chemistry and Biology of Pteridines,” ed. W. Pfleiderer, Walter de Gruyter, Berline, New York, 1975, pp. 219–245.