1. V. G. Drinfeld,Quantum Groups, Proc. Internat. Congr. Math. Berkeley, 1986, Am. Math. Soc., Providence (1987), p. 798.
2. M. Jimbo,Lett. Math. Phys.,10, 63 (1985).
3. N. Yu. Reshetikhin, L. A. Takhtadzhyan, and L. D. Faddeev,Algebra i Analiz,1, 178 (1989).
4. L. D. Faddeev, N. Yu. Reshetikhin and L. A. Takhtajan, ?Quantization of Lie groups and Lie algebras,? in:Algebraic Analysis, Vol. 1 (eds. M. Kashiwara and T. Kawai), Academic Press, New York (1988), p. 129.
5. V. G. Drinfel'd,Dokl. Akad. Nauk SSSR,268, 285 (1983).