1. Abramov, S.A., On the Summation of Rational Functions, Zh. Vychisl. Mat. Mat. Fiz., 1971, vol. 11, no.4, pp. 1071?1075.
2. Abramov, S.A., Applicability of Zelberger?s Algorithm to Hypergeometric Terms, Proc. Int. Symp. on Symbolic and Algebraic Computation, New York: ACM, 2002, pp. 1?7.
3. Abramov, S.A. and Le, H.Q., Applicability of Zeilberger?s Algorithm to Rational Functions, Proc. FPSAC?2000, Lect. Notes, Comput. Sci., Springer, 2000, pp. 91?102.
4. Petkov?ek, M. and Zeilberger, D., A = B, Wellesley, Mass.: A.K. Peters, 1997.
5. Gosper, R.W., Jr., Decision Procedure for Indefinite Hypergeometric Summation, Proc. National Acad. Sci. USA, 1977, vol. 75, pp. 40?42.