Keith O. Geddes, Ha Q. Le, Ziming Li. Differential rational normal forms and a reduction algorithm for hyperexponential func. In Jaime Gutierrez, editor, Symbolic and Algebraic Computation, International Symposium ISSAC 2004, Santander, Spain, July 4-7, 2004, Proceedings. pages 183-190, ACM, 2004. [doi]
Abstract is missing.