1. Sklyanin, E K. 1988. Boundary conditions for integrable quantum systems. Journal of Physics A: Mathematical and General, 21(10), 2375.
2. Cherednik, I. 1984. Factorizing particles on a half-line and root systems. Theoretical and Mathematical Physics, 61(1), 977–983.
3. Sweedler, M E. 1969. Hopf algebras. Benjamin, New York.
4. Bernstein, I N, Gelfand, I M, and Gelfand, S I. 1975. Differential operators on the base affine space and a study of g-modules. Lie groups and their representations (Proc. Summer School, Bolyai Ja´nos Math. Soc., Budapest, 1971), 21–64.
5. Lusztig, G. 1994. Introduction to quantum groups. Birkha¨user, Boston.