@article {MR2510007,
    AUTHOR = {Gao, Xiaoshan and Yuan, Chunming and Zhang, Guilin},
     TITLE = {Ritt-{W}u's characteristic set method for ordinary difference
              polynomial systems with arbitrary ordering},
   JOURNAL = {Acta Math. Sci. Ser. B Engl. Ed.},
  FJOURNAL = {Acta Mathematica Scientia. Series B. English Edition},
    VOLUME = {29},
      YEAR = {2009},
    NUMBER = {4},
     PAGES = {1063--1080},
      ISSN = {0252-9602},
     CODEN = {AMHSE9},
   MRCLASS = {12H10},
  MRNUMBER = {2510007 (2010b:12005)},
MRREVIEWER = {Alexander B. Levin},
       DOI = {10.1016/S0252-9602(09)60086-2},
       URL = {http://dx.doi.org/10.1016/S0252-9602(09)60086-2},
}