1. A. Hillisch and R. Hilgenfield, Modern Methods of Drug Discovery, Birkhauser Verlag, Basel, Boston, Berlin (2002), pp. 157–182.
2. M. D. Mashkovskii, Vol. 2, Drugs [in Russian], Novaya Volna, Moscow (2000), pp. 282–283.
3. R. L. Blakley, Chemistry and Biochemistry of Folates, Vol. 1, Wiley, New York (1984).
4. G. H. Hitchings, Angew. Chem. Int. Ed. Engl., 28(7), 879–885 (1989).
5. D. P. Baccanari, S. Daluge, and R. W. King, Biochemistry, 21(20), 5068–5075 (1982).