Changes

* Morris J, Dobson J (2001) Gastrointestinal Tract, in Small Animal Oncology, Blackwell Science, pp 137-140  

* Morris J, Dobson J (2001) Gastrointestinal Tract, in Small Animal Oncology, Blackwell Science, pp 137-140  

* Withrow S.J, Vail D.M (2007), Cancer of the Gastrointestinal Tract, in Withrow and MacEwen's Small Animal Clinical Oncology, fourth edition, Missouri, Saunders Elsevier, pp 483-489

* Liptak J. M, Withrow S.J, (2007), Cancer of the Gastrointestinal Tract, in Withrow and MacEwen's Small Animal Clinical Oncology, fourth edition, Eds Withrow S.J, Vail D.M, Missouri, Saunders Elsevier, pp 483-489